You Just Told Me

"Accuse a guy of having bad locks and before you know it, he's telling you where his motion detectors are."

— Burn Notice, "Breaking and Entering"

Ben has a secret. Stan, typically a rival or enemy, indicates, in some fashion, that he knows it—either by stating so directly or by implying it with his words or actions. Ben reacts in a way that confirms Stan's suspicions—sometimes, though not always, by outright asking "how did you know?", in which case the answer, of course, is this trope's name.

The ploy used to force The Reveal can be an outright declaration that they know, a specific word/phrase, or (if the character is hiding their identity) a name or something spoken in the other character's native language. It can even be a non-verbal prompt, such as a familiar face, location, scent, etc. The point of the trope is that the mark is hiding something, and the deceiver tricks them into revealing it by acting as if he already knows the truth.

One of The Oldest Tricks in the Book.

Subtrope of Reflexive Response and Batman Gambit. See also Pull the Thread, Out-of-Character Alert, Bluffing the Murderer. If one deliberately makes a mistake to goad another into correcting them when they otherwise wouldn't, see Correction Bait. If the deceiver wasn't suspicious until the infiltrator responded the way they did, it's Something Only They Would Say. If the deceived says something that only an impostor wouldn't be suspicious of, it's Bluff the Impostor. I Never Said It Was Poison may occur if the infiltrator mentions some facts about the case that the deceiver hadn't revealed. Suspiciously Specific Denial is totally not a related way of letting information slip. This also gives Ben a case of Implausible Deniability.

Not to be confused with How Did You Know? I Didn't, where someone appears to act on certain information that another person knows is secret, then reveals at the end that they didn't know it after all. The inverted trope is I Never Told You My Name, when it's the infiltrator's cover that's blown by revealing that they know too much about the deceived. Compare Freudian Slip, I'll Never Tell You What I'm Telling You! and Cold Reading. Sister trope to Thought They Knew Already.

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Examples:

Advertising

• In a tv promo for the Harriet the Spy movie, Harriet talks about the importance of keeping a notebook and listing info about everything and everyone. Sport claims she doesn't have anything about him, only for Harriet to reveal that she knows how he's worn the same smelly socks for over a week. Sport then says, "I suppose you know about the underwear too." To which a stunned Harriet replies, "I do NOW!" And proceeds to start writing it down.
• Used in a promo video given out by Nintendo Power promoting Star Fox 64; the two bad guys, apparently representing rival companies Sega and Sony, kidnap a tester (Peter) and lab guy (Bob) to find out the game's secrets.
  Bob: Peter, you didn't mention the Rumble Pack, did you?!
  [Peter facepalms]
  Sony Guy: No... "Bob"... you just did.
  Bob: I did?
  Peter: You did.

Anime & Manga

• Case Closed used this early on, when Ran suspects (correctly) that Conan is really Shinichi, so she tests it by seeing how he responds when called by his real name. It works, and he falls for it again when she mentions one of their teachers, but he manages to throw her off anyway.
• Even Lelouch, The Chessmaster of Code Geass, is not immune to these.
  Rivalz: [Lelouch]'s even holding a household account book...
  Lelouch: How do you know about that?
  Rivalz: Huh, you really do?
• Death Note: Light Yagami of all people is once tripped up by this ploy, when Namikawa tells him that he already knows that Higuchi is the Yotsuba Kira — it's only a very strong hypothesis at this point, but Light's surprised reaction is all the confirmation he needs. Of course, Light is an amnesiac at the time.

  Misa: Wow, that Namikawa guy is pretty smart!
  L: No, Light just messed up.

• This is how Videl confirmed that Gohan was Saiyaman in the Dragon Ball Z manga.
  Videl: So your identity is a secret, right?
  Saiyaman: Uh, yeah. That's correct...
  Videl: So, Gohan, how'd you get out of school?
  Saiyaman: Simple! I just said I was going to the bathroom and got here as... crap.
• Fullmetal Alchemist: Riza pulls this on Envy, who is disguised as Roy Mustang:
  Envy (as Roy): [being held at gunpoint] What are you doing, Lieutenant? Do you know who your gun's pointed at?
  Riza: Ha! Who? Don't make me laugh. When it's just us, the Colonel calls me by my first name, "Riza!"
  Envy: [ditches the disguise] So you two are that close, are you?
  Riza: I Lied. [shoots Envy in the head] But it was still very nice of you to fall for it, Envy.
• JoJo's Bizarre Adventure:
  • Stardust Crusaders: When trying to determine if a cruise ship stowaway is actually one of Dio's lackeys, Jotaro claims that he can tell the difference between Stand users and normal people by the fact that the blood vessels on their nose pop when they smell smoke. All of Jotaro's comrades instinctively move to touch their nose — as does the supposedly Muggle ship captain, exposing him as the Stand user and The Mole. Anne, the stowaway who had been briefly suspected as being the enemy stand user, just looks on, confused, as she doesn't know what a Stand is.
  • In Diamond is Unbreakable, Josuke and Okuyasu head to a shoe store where Koichi and Jotaro got injured fighting Yoshikage Kira, the latter (who's injured himself) attempting to crawl away, and pretending to be a victim of an explosion in the store when that fails. When Josuke tells Kira he can heal him, Kira confirms Josuke's suspicions by telling him to hurry up and do so, whereas a normal person would have doubted him, due to the nature of Stands.
    Kira: Please...hurry and save me!
    Josuke: "Hurry", huh? That's weird... Last time I checked, I looked like I was just an Ordinary High-School Student, yet you believed I could treat your wounds. I still have trouble getting people to let me into pachinko parlors, yet somehow I strike you as a med-school graduate ready and willing to fix your little boo-boos? Huh? You totally took the bait — which means you have the ability to see my Crazy Diamond.
    Kira: (thinking) Crap... I got too excited...!
  • Steel Ball Run: When Gyro manages to briefly break past Love Train and cut off Funny Valentine's ear, he grows suspicious that Gyro's horse may be influencing his Steel Ball's rotation. Johnny discovers the same thing and goes to tell Gyro that Valentine already knows about the rotation effects due to the detached ear, but Valentine overhears his yelling, causing his suspicions to be confirmed.
• The Novelization adds one of these to Mobile Suit Gundam SEED. In the original series, when watching Kira fight, Andrew Waltfeld quickly deduces that the Strike Gundam's pilot is a Coordinator. He later figures out that Kira is the pilot, most likely by watching his actions during a Blue Cosmos terrorist attack both are caught in. Realizing Kira is a both a Coordinator and not a native, and puts two and two together. He then confronts Kira in a scene which is played like he flat out knows what he is saying is true. In the novel, he suspects it (bases on his observations), but isn't quite sure, and uses one of these to confirm it.
• Used heroically in Negima! Magister Negi Magi. The Wild Card Kurt just finished a Hannibal Lecture, and made a sort of We Can Rule Together speech about saving "everyone," all 92 million of them—Negi then makes an educated, but still wild guess about what the disaster is, and Kurt, shocked, accidentally confirms it—and Negi points out that this confirmation has let loose the minor detail that Kurt's great plan for salvation is planning on abandoning 17/18ths of the planet.
• In Otoboku - Maidens Are Falling For Me, Sion started suspecting that Mizuho might be Wholesome Crossdresser pretty quickly, but she only confirmed it when - while passing Mizuho in the bathroom - she casually said "Your fly's undone." In Mizuho's defense, 'she' had only been acting like a girl for a few days by then. Later on, she gets so good at it that Sion actually forgets that 'she' is a boy sometimes.
• Used by Maru in Otona Keikenchi towards Seiji so he can learn more about his relationship with Yumeji and tease him relentlessly about it.
• In Rebuild World, Shizuka deduces from Akira's reaction to Sara and Elena that he's the one who saved them. She confirms her suspicions by bluffing to him about the bullet he left behind, exaggerating its effectiveness as an identification tool until he confesses to her. She then advises him to allow himself to trust good people like Sara and Elena, as a hunter needs friends to survive.
• In Sailor Moon R, Esmeraude launches a plan to infect people with dark energy using a flu virus. Minako and Chibiusa go to the pharmacy to pick up medicine for the Tsukinos, and coincidentally encounter Esmeraude, who seizes the opportunity to try and kidnap Chibiusa while she's at it. Minako/Sailor Venus comes to the rescue, prompting the following exchange:
  Esmeraude: I see! You somehow used your power to locate our Dark Henge site.
  Sailor Venus: Sure did!
  Esmeraude: Damn! So, to be clear, you're saying you knew about our plan to make the entire city sick by spreading medicine laced with dark power from this hospital base?
  Sailor Venus: Yeah! It was so obvious!
  Chibiusa: Wow, Venus will say anything based on the situation.
• In an episode of Yu-Gi-Oh! series 0, a cop announces that a criminal has been tracked to the joint where Yugi and Jonouchi have gone for a burger, and their friends are working. The police sergeant says it might help that the crook is allergic to eggs; Anzu says (falsely) that he will be easy to catch, because the burger buns have lots of egg in them. At that, the crook freaks out and tries to bolt, despite having suffered no ill effects when he ate there the day before. It's Played With in that the allergic crook is the one the police are searching for, but he isn't the actual culprit behind the crimes they think were his.

Comic Books

• In Asterix, a Goth-Gaul interpreter pretends not to speak Gaulish to prevent Astérix from interrogating him. Later on he sneezes and when Astérix absent-mindedly says "Bless you" he thanks him, in Gaulish. Made funnier by his subsequent frantic insistence that he does not speak Gaulish - still in Gaulish.
• Gotham City Sirens: Harley's Dad almost tricks her into telling him where the money is using this trick. "Oh, the money's not in Switzerland, it's... Damn it, Pop, you were going to do it to me, weren't you?!"
• Lucky Luke. The cowboys have captured a Native American and try to question him, but the prisoner apparently does not speak English. Lucky Luke serves him a glass of whiskey and asks him if he'd like some rocks on it. "No, thank you," answered the soon-to-be official interpreter.
• In the first volume of Rabbit and Bear Paws, Bear blows his cover by excitedly shouting when his mother mentions the possible reward of maple candy.
• In Superman mini-series The Krypton Chronicles, Pym-El—an ancestor of Superman—apprehends a gang of saboteurs. As interrogating them, Pym-El states he'll demand answers from their rich backer if they keep refusing to talk. When the saboteurs ask how he knows about their boss, Pym answer he didn't... until now.
  Saboteur: "We do not admit a thing! Why would we want to destroy your city?"
  Security Enforcer: "We can always go to Kandor and ask your well-to-do [leader]"
  Saboteur: "Eh? How could you know about Kly-Anth?"
  Security Enforcer: "I did not— until now!
• In The Walking Dead, while the Governor already suspected Rick's group was in a prison, he could not confirm it. Instead, he informed Rick that he had released Glenn (he hadn't) after he admitted (he didn't) they were indeed seeking shelter in the prison. It was the look on Rick's face that confirmed his suspicions.
• A complex variant in Watchmen: Doctor Manhattan can "remember" events happening in his future. It's immensely confusing for others to be told by him that "we will go to X, and there you will tell me about Y", and later, when the other casually mentions Y, Manhattan is startled, because they've just reached the point in time when he learns about this. You Just Told Me indeed.

Comic Strips

• Doonesbury for November 17th, 2012. Zipper starts a rumor that Walden College is going private. He approaches the president of the college and tells him that he started the rumor, and the president asks him how he knew that they were planning to do just that. Zipper says "I didn't until just now. I can't believe that worked, I saw it on some cop show".
• Subverted in Knights of the Dinner Table: Brian's opponent in a naval wargame tries this, prompting Brian to "confirm" it by bursting out "How did you know that was my plan?" At the climax of the game, it is revealed that Brian had a different plan all along, and deliberately did this to mislead his opponent.

Fan Works

• A variation happens in The Black Sheep Dog Series when Lucretia invites herself into Sirius's home and demands to see Regulus (who is in hiding/witness protection after defecting from Voldemort). Sirius tries to deny that Regulus is in his house, but Lucretia claims that Remus has told her about Regulus. Sirius demands why Remus told her the secret (he actually hasn't), which immediately confirms to Lucretia that Regulus really is in the house.
• The Bugger Anthology: A Dalek and a pair of Cybermen argue over which party will identify themselves first. One of the Cybermen breaks the stalemate by telling the Dalek "ladies first"; when the Dalek objects by saying its kind has no concept of gender, the Cyberman comments that it has identified itself as a Dalek. Then the Cybermen brag about their species' cleverness - allowing the Daleks to identify them in turn.
  Cyberman: Bugger.
• Common Sense has Ash tell the bearded man outside of Saffron Gym that he'll save "[his] daughter", he lurches away and asks how he knew. Ash calmly replies, "You told me, just now." He then adds that he always figured the man was close to Sabrina from how closely he guarded her.
• Dragon Ball Z: Dynasty: During his encounter with Zarbon, Vegeta brings up that Bardock is now alive and that Frieza did a lousy job of killing him when he destroyed Planet Vegeta. Zarbon is shocked that Vegata found out that Frieza destroyed the Saiyan homeworld, but Vegeta remarks that he only had suspicions until Zarbon confirmed it for him.
  Zarbon: Y-you know that Lord Frieza destroyed Planet Vegeta?!
  Vegeta: I had my suspicions before, but you've basically just confirmed them.
• The Persona 5 fic Covering the Phantom Thieves has this exchange when Kamoshida attempts to extort Intrepid Reporter Keiko into providing positive PR for the volleyball team, in retaliation for her previous positive article about alleged delinquent Ren Amamiya.
  Keiko: Why are you so hung up on this student's record?
  Kamoshida: What do you mean? I'm not allowed to worry about my school?
  Keiko: I'm curious what you had to gain by leaking it.
  Kamoshida: Jaw Drop How did you know that?
  Keiko: I didn't, but I do now. Thanks. I'll have those stories out next week.
• Harry Potter and the Prince of Slytherin:
  Harry: So, Hagrid's breeding dragons, I take it?
  Hermione: How did you know that?
  Harry: I didn't. I guessed and you just confirmed it.
• In Hermione's Furry Little Problem Fred and George tease Harry about his and Hermione's relationship.
  Harry: Look, Hermione's just a friend...
  Fred: Whose bed you sleep in?
  Harry: How did you know that?
  Fred: I didn't, but I do now.
• Legacy of the Rasengan: Jiraiya tries to talk to Naruto about training. Naruto retorts that he could have done that without spying on him for "days on end". Jiraiya praises Naruto for noticing how long Jiraiya was shadowing him. Naruto retorts he was bluffing. He only noticed two days ago. Jiraiya is both amused and embarrassed at Naruto playing him.
• In The Stalking Zuko Series, When Katara asks Mai about how she resolved her disputes with Zuko, Mai says that her preferred method- the silent treatment- is unsuitable for Katara. Katara asks how Mai knew that she and Zuko were an item, and Mai quotes the trope verbatim.
• In Thousand Shinji: When Kaworu shows up, he gives away his true nature to Shinji by referring to humanity as "Lilim".

Films — Animation

• In Disney's Aladdin, Jasmine, suspecting "Prince Ali" to be Aladdin, idly mentions Aladdin's friend/pet Abu (whom "Ali" would not know about); Aladdin responds without thinking.
• The Iron Giant: Annie Hughes is talking to junkyard owner Dean McCoppin. She mentions Hogarth (her son) sneaking out to the junkyard, and he asks if she knew about it, and she says "I do now."

Films — Live-Action

• In the Bond-wannabe film Agent for H.A.R.M., the lead character exposes the ersatz Bond girl as a villainous double agent by using her real name. The agent (and the film) treat this moment as incontrovertible proof, even though the two are alone (so, no matter what name he utters, he can't possibly be talking to anyone else) and her confused reaction is a completely natural one. ^note She does irrevocably out herself a minute later by attacking him, but his mind was already made up; further, he had (off screen) checked a sporting competition she was registered in — under her real name rather than her alias.
• In All the President's Men, Woodward and Bernstein have a document identifying certain individuals only by the first initial of their surname. They believe "P" is a man named Porter, so while questioning a woman who may know, they casually intimate in a brief throwaway aside that they know "P" to be Porter. Her last words as they leave is an incredulous "How did you know about Porter?"
  • The two discuss the plan before they go and do it. Rarely, they discuss what happens if they're wrong. After a beat, they admit if that's the case, "We're screwed."
• In Along Came a Spider, it's what the kidnapper Soneji doesn't say that gives Alex Cross crucial information. Cross suspects that Soneji is an unwitting pawn in a bigger conspiracy. He says something that Soneji would have known was incorrect if he had all the facts, and his non-reaction gives him away.
• Austin Powers: International Man of Mystery: In this case, Austin is aware of the fact ahead of time and is invoking this trope purely to look classy.
  Austin Powers: Your boss, Number 2. I understand that cat's involved in big underground drills.
  Alotta Fagina: How did you know?
  Austin Powers: I didn't, baby. You just told me.
• In The Avengers, Black Widow has been captured by a Russian General. She pretends to have outdated information on who runs the various illegal trades and what they sell, and the General is more than happy to correct her. When Coulson calls her to come in, she breaks character and protests that she is busy conducting an interrogation and that "this moron is giving [her] everything," to the hapless general's confusion and dismay.
• In Billy Jack, Billy uses this ruse to trick Jean Roberts into revealing that she was raped by Bernard Posner.
• As with the above example, Crouching Tiger, Hidden Dragon also uses this tactic. Shu Lien suspects Jen is the thief who stole the Green Destiny sword, and confirms it by purposefully dropping a full cup of tea, which Jen catches effortlessly without spilling a drop.
• Fatal Instinct. Ned Ravine's secretary Laura Lincolnberry tells him that he has lipstick on his collar. He looks at his collar and says he doesn't. She says "You just told me" (if he hadn't been fooling around, he wouldn't have had to look at his collar).
• In the 1993 adaptation of The Fugitive, U.S. Marshal Sam Gerard (Tommy Lee Jones) tricks fugitive surgeon Dr. Richard Kimble (Harrison Ford) into revealing himself when Gerard calls down a stairwell to a retreating figure, "RICHARD!" Kimble involuntarily looks up, giving himself away.
  • In the original script, Kimble doesn't look up when Gerard calls to him, even though other people in the stairway do. However, he does freeze in place for a moment (no doubt stopping himself from reacting to the sound of his name), before continuing down the stairs at a visibly faster pace than before. The misstep and deliberate lack of response tips Gerard off just the same.
• Famously used in The Great Escape when Bartlett and MacDonald are boarding a bus posing as French businessmen. Everything is going well until one of the guards wishes them "good luck" in English, causing Mac to respond, "Thank you!" ^note Truth in Television: this was precisely how the leader and companion were caught in real life. Bartlett briefly evades capture by averting this when stopped by another patrol, but unfortunately, he's rather well-known to the Germans because of his track record, and has the misfortune to run across another soldier who recognizes him.
• James Bond:
  • In Die Another Day, Bond uses this method to reveal the identity of Gustav Graves/Colonel Moon. The trope as played out here is somewhat less than effective, since the audience has already been alerted to this plot point — not to mention that by this point Graves/Moon isn't really trying to hide it anymore even from Bond.
  • In Quantum of Solace, M calls CIA to ask about a member of Quantum they're investigating. She gets transferred to Gregg Beam, who denies any operations. M then tells her subordinate that this proves the opposite, as there would be no need for the CIA Section Chief for South America to personally get this call otherwise.
• A variation in Kiss of the Dragon. The climax involves Jet Li's character storming the French police station full of Corrupt Cops. He calls the Big Bad (the police chief) and asks him to look out the window. When he does, Jet Li's character tells him that, now that he knows where he is in the building, he's coming up.
• In Legally Blonde, a lawyer outs a witness as gay (to prove he couldn't have been the female defendant's lover), by asking him several rapid-fire innocuous questions (like "How long have you worked for her?" etc.), ending with "And your boyfriend's name is?" which the witness answers "Chuck" without thinking. When the attempts to reestablish cover by claiming that he was confused by the rapid-fire way in which the questions were asked, and that Chuck is only a friend rather than his boyfriend, Chuck himself stands up and takes very vocal offense, leaving the witness's credibility utterly shot.
• Lone Hero: Bill, while attempting to negotiate with King and the Iron Bandits, tells King that he doesn't need the rest of the hostages since he already has John's girlfriend. Up until that point, King had not known that the woman he had snatched was John's girlfriend.
• Used in Men in Black, where Agent K finds out which of a number of illegal Mexican immigrants is actually an alien because he cannot speak a word of Spanish. K determines this by insulting the "man" more and more outrageously in Spanish without getting any reaction other than chuckling and agreeable nodding.
• In Mr. & Mrs. Smith (2005), John, already suspicious about his wife, "accidentally" drops an open bottle of wine that she catches perfectly; then she realizes his ruse and lets it spill.
• Attempted in Never Too Young to Die. In a subversion, the intended "victim" manages to bluff his way out of the situation, though not convincingly:
  Ragnar: Stargrove!
  Lance: Is that name supposed to mean something?
  Ragnar: My mistake.
• Night School (1981): Following a loaded question from Lt. Austin, Eleanor explains the ritual significance of a headhunter placing their victim's head in water. She then asks him how he knew about it, and he replies that she just told him.
• In Quicksand, the police arrive to question Vera just after Dan has left her room. As Dan has just told her that he thinks he has killed Mackey, she assumes that is why they are and immediately tells them "I didn't have anything to do with him!" The police, who are actually there to question her about the break-in at Nick's and don't know about the attack on Mackey yet, get suspicious and the detective starts asking her series of leading questions. Vera's guilty conscience fills in the blanks and she makes a series of denials that dig her in deeper, as she keeps denying involvement in crimes she shouldn't even be aware of. When she realises what is happening, she flips and starts blaming Dan for everything.
• The Rock: When John Mason meets Stanley Goodspeed, he quotes the Latin saying "Timeo danaos et dona ferentis." ("I fear the Greeks even when they bring gifts."). When Goodspeed identifies it, Mason immediately figures out that Goodspeed isn't an ordinary FBI agent.
• Inverted in the climax of Se7en. When Det. Somerset leaves serial killer John Doe in the custody of Det. Mills to open a suspicious package, he realizes that it contains the head of Mills' wife. All of this happens a considerable distance away from Mills, who is holding Doe at gunpoint to make sure he doesn't run, but Doe blatantly tells Mills what's in the box; for a moment, Mills is too stunned to believe what Doe has said, until Somerset returns begging him to drop the gun. As Mills repeatedly begs Somerset to just tell him what's in the box, Doe simply says, "He just told you," since Somerset's refusal to admit it is proof that Doe is telling the truth.
• In the Sgt Bilko movie, Bilko's soldiers give Thorn's goons false information, making him remove a 'key component' of the Hover Tank so it wouldn't work at the demonstration the next day. After Bilko and his troops make it so the tank appears to work, Thorn confronts the General overseeing the demonstration, insisting that Bilko is incompetent and that they faked the whole thing. When asked for proof, he reveals the component he removed... showing the four star General and the crowd of witnesses that he deliberately sabotaged the project out of spite towards Bilko.
• Exaggerated in Spies Like Us when Austin Millbarge suspects that a pair of agents supposedly sent to help him and his partner are actually KGB agents. He tells them something funny in Russian (Which translates as "The less you know, the better."), causing them both to explode in laughter, saying "Da! Da!"
• In State of Play, while the reporter Cal is heading up to a crime scene.
  Cal: I heard Metro ballistics was just here.
  Detective: Who told you that?
  Cal: You just did.
• In Superman II, Lois tries this to reveal Clark's secret identity, first by calling him "Superman" and then by jumping into Niagara Falls. Naturally, Clark manages to rescue her without being obvious. In the restored cut, she tries jumping out a window, with the same result. Then she tries shooting him with a blank. Clark doesn't know that it's a blank, however, so he fesses up to being Superman.
• In Taken, the Papa Bear protagonist confirms his daughter's Albanian kidnapper's identity by getting a translator to write the phrase "good luck" in Albanian and asking the kidnapper to translate it into English. During the kidnapping, this was all the kidnapper said to him on the phone, so he wanted to confirm the voice.
• In Where Eagles Dare, Nazi General Kramer is eventually convinced Schmidt is an ally and hands over a list of names of spies working in Britain, as well as confirming the identity of The Mole. Smith immediately reveals he had no evidence for this and the purpose of his mission was to extract the information from the Germans.
• Straightforward example in Who is Cletis Tout? Sloppy work on Finch's part to respond to his name, considering he was a fugitive in the middle of a room of cops.

Literature

• In the third book of The Acts of Caine, Caine meets a spy for an old friend of his, and instructs the spy to take a message to her. The spy plays dumb for a while, until Caine offers to explain what gave to spy away (so that he can correct the mistake). The spy admits it would be useful to know how Caine was so sure. Caine just says "I wasn't sure."
  Caine: Fuckin' amateur.
• Mark Twain's Adventures of Huckleberry Finn. While Huck is wearing a dress and pretending to be a girl, a woman determines he's actually a boy by tossing a lump of lead into his lap. He clasps his legs together to catch it, the way a boy who's used to wearing pants would do, instead of spreading his legs apart, the way a girl who normally wears a dress would.
• The Alice Network:
  • Subverted:
    • René Bordelon speaks in German to see if any understanding shows on Eve's face, but fortunately she's a good enough actress that she doesn't react.
    • He also at one point says Eve’s real name when talking about Adam and Eve and she barely manages to not react, but this was probably not intentional on René’s part.
  • Played Straight:
    • René figures out that Eve isn’t from the region that she says she’s from because her accent isn’t right.
    • Although René Bordelon was suspicious before, it was an accidental English phrase that actually blew “Marguerite”’s cover.
• In Douglas Hulick's first novel, Among Thieves, the protagonist, Drothe, pretends to be working for one crime lord, but actually owes allegience to that crime lord's nemesis. Midway through the novel, a secondary character figures this out, and asks Drothe how long that's been the case. Drothe asks how she found out: she replies, "you just told me now, you son of a bitch!"
• Animorphs:
  • Cassie (morphed as Rachel) is talking to a Controller, and he suspects her, so he randomly blurts out "Andalite!" If Cassie had reacted, she'd have given herself away, but she plays it cool and responds "Yeah, a light would be good too."
  • She does, however, fail spectacularly when Visser One takes her by surprise by accusing her of being human. It turns into a long silence while they frantically figure out how to respond, before eventually deciding that nothing they can say will give them away as totally as that long silence already has.
• Isaac Asimov:
  • "Evidence": A scientist interviews a politician he believes to be a robot in disguise. When the scientist refuses to name the source who brought the rumors to him, the politician asks if they can just assume it's his political rival and move on. He keeps on using the rival's name for the name of the source in their conversation, until the scientist forgets that he's supposed to be keeping it a secret and uses it himself. The politician, who used to be a lawyer, calls this a "shyster trick".
  • "I'm in Marsport Without Hilda": A detective is trying to figure out which of several people in a room is a drug smuggler. All of the innocent suspects are currently loopy and speaking stream-of-consciousness gibberish, because they were given a drug to prevent space sickness, and the guilty party is faking it. Unable to figure out who is guilty, the detective, out of frustration, starts telling them about the hot date he would have had, if he wasn't stuck interviewing them. The guilty party's, um, "reaction", gives him away.
  • The Robots of Dawn: Baley has circumstantial evidence that a person was communicating with a unique robot for reverse-engineering purposes. The person is, unfortunately, a very respected member of society (and on on another planet at that), so his word carries more weight than his. So, after presenting the evidence, he says the man might have committed the very crime he accuses his opponent of as a side effect. The criminal blurts that couldn't have been caused by his experiments... mind you, that other crime is considerably lighter, mere destruction of property, so the criminal is forced to fold on the spot.
  • "The Singing Bell": This story involves a thrown object, with the twist that the criminal is the thrower. He gives himself away as having spent a long time on the moon when he throws it far too short in earth's gravity.
  • A Whiff Of Death: The killer gives himself away by reacting to the detective grasping and starting to turn a valve that had been rigged to cause an explosion (the trap had previously been detected and neutralized).
  • In one of Asimov's short mystery stories, the culprit is a Québécois person using a false identity of an American. The detective tricks him into revealing his true identity by asking him to write the word "Montréal," and he writes it with an accent aigu on the e, whereas someone who only spoke English wouldn't spell it that way.
• In the last book of Codex Alera, Tavi and several members of his high command are on a ship under attack by Vord scouts. Magnus has been suspicious of Valiar Marcus for several books, since he seems to know a little too much about espionage for a decorated soldier, and particularly Cursor methods of going about it. So, at the very end of the fight, he shouts, "Fidelias! Behind you!," having narrowed down the list of high-level Cursors he could be to one specific traitor. Tavi, who had agreed to the plan thinking it would exonerate his loyal subordinate, is very, very angry when Marcus immediately whirls around.
• In Ben Elton's Dead Famous, Inspector Coleridge manages to get an on-stage confession from Geraldine Hennessy revealing her as the killer in this fashion. After working out how she'd used one of the house tasks to kill Kelly unnoticed- but still without definitive proof- he films a fake evidence tape of the murder using his assistants as actors and airs it at House Arrest's finale show. Geraldine, predictably, takes the bait and and starts raging about how her lackey was supposed to have burned the tapes- whilst he's in the control room, pointing out that he DID burn them and what a complete dupe she's just made of herself.
• Discworld:
  • Done subtly in The Fifth Elephant. The Patrician assigns Commander Vimes a manservant, Inigo Skimmer, for his trip to Uberwald. Vimes tosses an orange at him, and it bounces off. He doesn't say anything at that point, but later, when he reveals that he knew about Skimmer being a spy, he points out that a normal person would have either caught the orange or at least flinched (to confirm this theory, he later lobs one at Sergeant Stronginthearm, who ducks); Skimmer looked at it, recognized that it wasn't a threat, and let it go on its way, inadvertently showing that he has had assassin training.
  • Played with a bit in Night Watch too. Coates informs Vimes that "I know you're not the real John Keel." Vimes keeps a totally straight face, only to realize that that gave him away more thoroughly than anything he could have said.
    • Although in that case Coates didn't even need the confirmation, as he did actually know for a fact that Vimes wasn't the real Keel because Keel had been Coates' own mentor in the past.
    • Also done at the end of the book, when Vetinari calls Commander Samuel Vimes Sergeant, and Vimes replies instantly. Vimes accuses Vetinari of having known all along, and is told "Not until, oh, one second ago."
• In the Doctor Who Expanded Universe short story "Walkin' City Blues", the Doctor bursts into the Big Bad's office and announces he's seeking justice for Boko Berikuka. When the man launches into a rehearsed spiel about "Boko Berikuka" being a meaningless phrase used by the citizenry, the Doctor points out an innocent man would have called the police, not tried to dodge a question that hadn't actually been asked.
• Dragaera novels:
  • This is the modus operandi of Vlad and Kiera in Orca. They basically spend the whole book going around in various disguises talking to the conspirators, pretending to know more than they do (which is nothing) until they get a reaction, and then put all the pieces together.
  • In Iorich, the Empress thanks Vlad for his help in exposing a conspiracy in the East (detailed in the previous novel, Jhegaala). Vlad asks her how she knew he was the one who sent those anonymous letters, and the Empress replies that she didn't, until now.
• In The Elric Saga, this is how Elric finds out that his cousin Yyrkoon is trying to obtain the magic Black Swords, Stormbringer and Mournblade.
• In the novel The Guns of Navarone, the saboteurs, who are posing as Greek fishermen, are confronted by a German caique. When the Germans tell them in English to lower the sails, Captain Mallory is terrified that the captain of their fishing boat and youngest member of the group, Lieutenant Andy Stevens, will fall for it and reply, because the fishermen they are poising at would not know English. Not only does Stevens stare at the German in utter incomprehension, when the man continues to give orders in English, the Lieutenant has the cheek to tell him (in Greek) that he doesn’t understand German and asks him to speak in his language.
• Hercule Poirot confronts a murderer, in Death in the Clouds.
  Poirot: You left your fingerprints on the bottle.
  Murderer: You lie! I wore–
  Poirot: Ah, you wore gloves?
• In the Joe Pickett novels, one of Joe's favourite tactics when dealing with people suspected of violating game laws is to knock on their door and, when they open it, say "I guess you know why I'm here". He finds that people will often confess to crimes he didn't even know about.
• 19th-century amateur detective Julian Kestrel uses this in his first novel, Cut to the Quick.
  "So," said Guy, his eyes wide but his laughter abating, "I suppose Bliss told you everything."
  "I haven't spoken to Bliss," said Julian. "Felton couldn't find him. All he found was this." He indicated the patchwork sack.
  "You mean—that's all you have?" Guy gaped at the sack. Laughter convulsed him again. 'You mean, if I'd only held my tongue— No, really, this is funny! It's an absolute screamer, don't you see? On the strength of a worm-eaten pedlar's sack, I've put a rope around my neck."
• In Stephen Fry's The Liar, the main character tries to hide his identity from the police, only to respond to his own name, which they got from the inside cover of a book he had with him. This is based on His Fryness's own experience.
• In Sir Walter Scott's The Monastery, the courtier Sir Piercie Shafton, who speaks in high-flown Euphuist terms, is disguised as a milk-maid; questioned as to who he is, he replies, "I am she, O most bucolical juvenal, under whose charge are placed the milky mothers of the herd." His disguise is unsuccessful.
• Montague Egg has reason to suspect that a man in the same room is a wanted fugitive, and so shouts his name, telling him to look out. The man answers...
• One Flew Over the Cuckoo's Nest: McMurphy runs through the hallways of the asylum warning the patients that an orderly is on their way to check on them. Everyone stops what they're doing and pretends to sleep, including Chief Bromden, the narrator. After it turns out to be a false alarm, McMurphy casually says to Bromden, "Hey Chief, I could've sworn they told me you was deaf!" Bromden had been pretending to be deaf and mute for years before McMurphy showed up.
• In M. K. Wren's Phoenix Legacy trilogy, Val Severin finds new Phoenix member Alex Ransom looking up some information relating to the fallen Peladeen Republic ... and the fact that the missing and presumed dead heir of the Peladeen Lord had the same name as one of the Phoenix Councilors. Shocked, Val asks how much Alex has been told about "the Peladeen Alternative"; it's top secret. Alex smiles and admits that all he knows is that the Councilor in question is key to the Peladeen Alternative. He never gets around to telling Val that he hadn't even heard that term until she blurted it out.
• In Outcast of Redwall, Veil is up to his usual tricks, stealing small objects from Redwallers. When the Abbess claims that a special dye used will turn the thief's paws red, Veil starts scrubbing and scrubbing, seeing his paws turn red before his eyes. Then he overhears a conversation revealing how to remove the dye, and hurries to wash his hands... except, of course, that it actually was dye this time. Being caught, aha, red-handed causes him to be cast out from the Abbey.
• In the Relativity story "Tempest", Matthew Bruce (who works for a secret government agency) has recently run into a mysterious man who calls himself Phanthro. Since he doesn't know if Phanthro is another spy or someone unrelated, he outright asks his boss who Phanthro is. His boss responds with a genuinely puzzled "I don't know," meaning that he didn't actually know. If he had known, he still would have answered "I don't know," but it would have sounded practiced and forced.
• The Destroyer: This is the reason all of Remo Williams's aliases are Remo 'Something'. While capable of dodging bullets and shattering steel, he often forgets an elaborate alias while on a case.
• Sherlock Holmes:
  • In The Three Gables, where to get the whole story he sends the villainness a note reading simply, "Shall it be the police, then?" He only has hunches, but by story's end she's told him enough to prosecute (if he wished). Earlier in the same story, he has the following exchange with a servant he suspects of working with the gang, when he asks her who she was seen talking to:
    Susan: That's my own business.
    Holmes: Suppose I tell you that it was Barney Stockdale to whom you spoke?
    Susan: Well, if you know, what do you want to ask for?
    Holmes: I was not sure, but I know now.
  • Another strategy of his is, rather than just ask someone for a description, to make up a description and check if it's accurate.
  • In a variant of the above, in "The Blue Carbuncle", when he sees the witness has a copy of the Sporting Times, he says something he knows is wrong, and claims to have a bet with Watson on it. The man, who would have refused to answer questions, is only too pleased to settle a bet.
• Star Wars Legends:
  • In I, Jedi, Corran Horn goes undercover as Keiran while training at Luke Skywalker's Jedi academy, changing his name since he's a mildly famous pilot. Interestingly, after leaving the academy, "Keiran", going by yet another name, is questioned about Luke. He goes on to display an appalling lack of knowledge about one of the single most famous and important people in the galaxy in order to keep up the ruse.
  • In Dark Force Rising, when Mara Jade, a former assassin for Emperor Palpatine, meets with Grand Admiral Thrawn, he says, "Come closer, Mara Jade." (The two had met several years before and she was under an assumed name.) She begins instinctively walking forward, catches herself and comments that Thrawn shouldn't have to rely on such cheap tricks to verify who she was. He agrees, and then asks her questions that only she would know the answer to.
  • Used again in the same book. No one in the New Republic knows the name of the new Grand Admiral on the scene. Han Solo meets with a ship thief who does know, and is offering to show Han the location of a lost fleet before the Empire finds it.
    Han: What makes you think the Empire's involved?
    Ferrier: With Grand Admiral Thrawn in charge over there? He's involved in everything.
    Han: Thrawn, huh? Thanks, Ferrier.
  • In Zahn's Outbound Flight, Thrawn is able to get an awful lot of information out of a Corellian guest/prisoner who really doesn't want to tell him these things by working this method into conversation, though he makes it look effortless and never actually says the trope name.
• In St Elmos Fire, Alec replies "What did Kevin tell you?" after his girlfriend asks him about his "extracurricular love life" and beats on Kevin in retaliation. Kevin hadn't spilled a thing; his girlfriend just had a hunch.
• The Stormlight Archive book 1, The Way of Kings (2010): Kaladin proves his suspicions that Teft was once a squadleader using this method.
  "Teft," Kaladin ordered. "Split them into pairs by size and weight, then run them through an elementary forward spear stance."
  "Aye, sir!" Teft barked. Then he froze, realizing what he'd given away. The speed at which he'd responded made it obvious that Teft had been a soldier. Teft met Kaladin's eyes and saw that Kaladin knew. The older man scowled, but Kaladin returned a grin. He had a veteran under his command; that was going to make this all a lot easier.
• To Kill a Mockingbird: Atticus confronts Scout and Jem telling them not to make fun of Boo Radley or put his life history on display, and when Jem protests that he didn't say they were doing that, Atticus responds, "You just told me," causing Jem to realize he's fallen for "the oldest lawyer's trick in the book."
• Tortall Universe: In Trickster's Choice, Aly mentions weapons in hidden storerooms under the stables. Lokeij says he has the stables watched all the time, and there's no way Aly could have known about them. Aly replies "I didn't know until now."
• Egwene uses this in the Wheel of Time book The Gathering Storm. Black Ajah are the only Aes Sedai who can lie; any other Aes Sedai will find the words freeze in her throat if she attempts to lie. Egwene knows that a certain Aes Sedai is Black Ajah and needs to prove it to the rest. She asks her a rapid-fire series of questions, to which any Aes Sedai would give vehement denials. ("Do you consort with the Forsaken?" "Do you serve the Dark One?") Then she asks a question about her target's hair color. Her target denies her own hair color, which proves to the assembled audience that she is Black.
  • Also used by Lady Dyelin to Birgitte. It's implied that this has happened multiple times off screen as well as the onscreen times. In the onscreen times, Birgitte handles herself well.
• In Wicked, Elphaba pretends not to know Fiyero, and is a good enough actress not to respond to her name... but she does later respond to her childhood nickname, Fabala, while he chases her. It's kind of a moot point, though, as he was already sure it was her.
• In Belorussian writer Olga Gromyko's Witch cycle, the titular witch Volha once uses this trick to find the shapeshifting monster natsyga. It becomes known that the natsyga hides among the castle servants. Volha tells one of the maids: "Why don't you assume your real shape?"
  The maid: How did you guess?
  Volha: I didn't. You are the sixth one I told this. Others just thought me crazy.
• In Christie Golden's World of Warcraft: The Shattering, Anduin Wrynn deduces that Jaina Proudmoore has been meeting with Thrall in this manner.
  Anduin: I don't mind. But then again, I don't have secret meetings with orcs in the middle of nowhere.
  Jaina: How did—
  Anduin: Yes! I was right! You were out meeting Thrall!
• In the Nero Wolfe novel If Death Ever Slept, Archie Goodwin tells an assistant DA that he knows the bullets used in two separate murders were fired from the same gun. The ADA tries to cover but gives the game away. Then he goes to the police to start an investigation into the leak. Inspector Cramer, who's savvier, tells him to look in the mirror.

Live-Action TV

• One episode of the Canadian spy series Adderly had the secretary, Mona, trying to determine between V. H. Adderly and a lookalike imposter. She asked them about his name: "The V is for Virgil. What is the H for?" When one of them said that the H was for Homer, she knew at once that that was the imposter — because the real Adderly knew she did not know his middle name.
• In an episode of The Agency, an undercover agent has replaced a person who's known to be allergic to dogs, so he reacts accordingly whenever there's a dog in the room. He's discovered when his suspicious contact places a dog nearby but out of sight and he fails to develop a stuffy nose.
• Angel, "Blind Date": Angel throws an object at a woman claiming to be perfectly blind; she catches it out of the air perfectly. Of course, she actually is completely blind, and he knows it... the point is how the court full of people react to this.
• A painful subversion occurs on an episode of Arrested Development. Michael tries to prove a blind woman is only faking her condition by throwing a book at her. Unfortunately, she's been temporarily blinded for real and the book hits her in the face.
• Beverly Hills, 90210. Steve suspects (correctly) that his new girlfriend is a social climber and a gold-digger. After her less-than-thrilled response to the bracelet that he gives her, he accuses her of already knowing who his mother (a famous former TV star) was long before she approached him:
  Girl: How did you know that?
  Steve: I didn't. You just told me.
• The Bill: While investigating a warehouse burglary, Detective Sergeant Greig focuses his attention on an employee with an undisclosed criminal record (drug offences and credit card fraud), while promising him to keep it quiet as long as he's not involved in the break-in. However, the manager picks up on it.
  Salter: Why all the attention? Is it because of his criminal record?
  Greig: You know about that?
  Salter: I do now.
• One Bones episode ends with her offering everybody in the victim's funeral a cup of tea "from his own private stash. The same that was his last drink." The same one that was poisoned by the victim's mother.
• Boy Meets World: Mr. Feeny uses this technique on at least two occasions. Both cases involved leading a student he suspects of having committed a certain offense into believing that a friend has ratted them out, to elicit as "You told him?" response from the suspect.
• Subverted in the "Who are You" episode of Buffy the Vampire Slayer. After Buffy swaps bodies with her Evil Counterpart Faith, Buffy is apprehended by the police and Faith remains alone with Buffy's mother Joyce. The first thing Joyce says is "Faith", and the changeling indeed reacts involuntarily, so it does looks like Joyce deducted her true identity. However, it turns out she didn't and is just willing to ask "Buffy" about Faith.
• Michael Westen on Burn Notice pulls a scheme called a "reverse interrogation", in which he lets the criminal interrogate him, and hopes the bad guy will give away important information in his questions. (He does.) Truth in Television, as intelligence agencies often consider the questions their opposite numbers have as being just as informative as actual information: it tells them what the other side does or doesn't know. One of the reasons double agents are rarely just given "shopping lists" for specific pieces of intelligence, instead of vague areas of interest.
• In the Columbo episode "A Deadly State of Mind", the crime is observed by a blind witness who cannot identify the perpetrator. Columbo confronts the suspect with the witness's identical twin. When the suspect wrongly accuses the twin of being blind, he accidentally reveals that he already saw the real witness - with his guide dog - at the scene of the crime.
• In the Criminal Minds episode "Bloodline", Hotch and Prentiss are doing the Good Cop/Bad Cop routine to try and get the name of a person out of the perp. Hotch then reads off a list of their suspects. The perp reacted at one of the names and shouts "I won't tell you!" and Hotch replies "You just did". The Oh, Crap! look is priceless.
• In an episode of CSI, a suspect is confronted with a suitcase that resembles one owned by his victim. Thinking it's the same case, he protests that they're not allowed to break into his car, and the investigators thank him for telling them where to look for the real one.
• Daredevil (2015): Fisk does this to Karen Page regarding Daredevil's secret identity, blurting out a theory in front of her and taking her shocked and horrified reaction as a confirmation. By that point, though, he already had all the proof he needed, so it's implied he just did it to mess with her.
• Dear White People: How Coco learned about Troy's affair with Neika.
• From Dexter:
  Doakes: That's all you care about, is your job. Even if it meant doin' Pascal's man to get it back.
  LaGuerta: How did you know about Bertrand?
  Doakes: I didn't for sure until just now.
• On an episode of A Different World, Whitley's new boyfriend Byron has noticed the tension between Dwayne and Whitley and asks him about it. Unfortunately, in doing so, he learns more than ever expected to—Dwayne confirms Byron's suspicions that he and Whitley had previously been involved, but assures him that the relationship is over and that "Last night was a mistake and it meant nothing".
  Byron: Last NIGHT?
  Dwayne: You didn't know.
  Byron: No, I didn't. You just told me.
• Doctor Who:
  • At one point in "Doomsday", a Dalek and a Cyberman are seen screeching at each other to identify themselves, each refusing to do so first. Finally the Dalek screeches, "Daleks do not take orders!", to which the Cyberman simply replies, "You have identified as Daleks."
  • A non-undercover example in "Robot of Sherwood". Clara uses a similar method to get information out of the Sheriff of Nottingham. She even explains that this is one of the Doctor's tricks: the easiest way to get information out of someone is to convince him that you already have it.
• Carson uses this on Mrs Patmore to find out Mrs Hughes might have cancer on Downton Abbey.
• In one episode of Dragnet, Friday and Smith are questioning a man suspected of beating a father and daughter, the father fatally.
  Smith: His daughter saw you.
  Suspect: She can't have. The lights were out.
• Eureka:
  • Used by Deputy Andy the robot to confirm that Sheriff Carter and the others had, in fact, traveled through time and changed the timeline.
  • An earlier episode had Carter stuck in a "Groundhog Day" Loop. He was able to figure out the scientist responsible for it when the scientist told Carter he'd sign his redaction papers later. Trouble was that Carter hadn't even gotten the redaction list from Thorn yet that loop and was approaching the scientist because he was GD's "time guy" and just wanted help on cracking the case.
• Flashpoint:
  • In one episode, the team has caught a member in a gang gunning for another girl. They knew there were at least two others and wanted the captured member to identify their pictures. The gang member had no intention of helping them but when her eyes lingered a little longer on one of her friends, Parker picked up the picture and she immediately blurted out "But I didn't say anything!"
  • In the series finale, the team believed the bomber placed ten bombs, based on the list of complaints they've been receiving and some hints from his manifesto. After five bombs were defused/detonated, Jules talked with the bomber and asked him "Where are the other five bombs?", to which he was surprised that they knew there were five left, confirming their theory.
• In the Green Wing episode "Rumours", while trying to persuade Guy Secretan to deny the rumors that they slept together, Caroline Todd tells him that she knows something embarrassing about him. He hurriedly denies the rumor that Sue White has penetrated him anally, which Caroline had not in fact heard.
• Hogan's Heroes: The gang's always careful about their captors setting up a plant in their barracks. In one episode they decide to test a new American "guest". In the middle of the night, they all start making noise and shouting "FIRE!" - Kinch yells at him, in German, "Quick! Out the window!" Newbie heads straight for the window.
• House:
  • In "The Socratic Method", the patient of the week is a mentally ill woman whose supposedly 18 year-old son is taking care of her. House puts an X-ray on the lightboard, and says he can tell the person is about 15. The kid confesses to lying about his age. After a brief conversation, House reveals that it wasn't even the kid's X-ray.
  • In the same episode, House temporarily shrinks the patient's tumor in order to make it small enough to be operated on. Soon after, Cuddy tells him that she knows about something he did that he shouldn't have. House tries to cover by saying that he didn't want anyone to know it's his birthday and he figured Cameron told Cuddy. Cuddy really was talking about his birthday, but she can tell by his reaction that he thought she was talking about his case and goes to find out what he did, which doesn't take long.
• Jake and the Fatman: In "Second Time Around", Jake is interrogating mob enforcer Billy Nickel, who is being uncooperative. Jake mentions the name of previous victim, saying he is out of his cast and getting around pretty well on his crutches. Nickel grunts that he'll break the punk's other leg for squealing. Jake then admits the victim hadn't said anything and it was just a lucky guess.
• Happens on an episode of Judge Judy. Two boys are being accused of stealing a girl's purse and stealing items out of it. The boys deny that they ever touched the purse. Judge Judy, already suspecting the boys of lying, asks the plaintiff to list off the things that were in her purse.
  Plaintiff: ...I had gift cards in there, my earpiece, and a calculator.
  Defendant #2: There was no earpiece in there, ma'am.
  Judge Judy: (Laughing) I love it! I love it. Judgement for the plaintiff.
• Used in Just Good Friends where Vince has been unfaithful to Penny. Again.
  Penny: Why did you take that girl home?
  Vince: (sigh) Who told you?
  Penny: (sadly) You just did.
• In The Kicks, Emma tricks Mirabelle into revealing Devin's injured ankle this way. Mirabelle notes that she walked right into it.
• In the pilot of the American version of The Killing, Detective Linden pulls one of these on Councilman Richmond:
  Linden: Oh, and councilman, you might want to call off your dog at the school. He won't find anything.
  Richmond: And how did you know about him?
  Linden: I was guessing.
  Richmond: And I just confirmed it.
• Knight Rider did this numerous times. On one occasion, a woman impersonated her recently murdered mother to flush out the killer; on another, a blind woman pretended to drive, suggesting to the criminals that she might have witnessed their deeds.
• Shows up in Law & Order: Special Victims Unit:
  Eliot: Is this a patient of yours? [shows picture of suspect]
  Psychiatrist: I am not at liberty to say.
  Eliot: You just did. Confidentiality only applies to patients.
  • Which is completely ridiculous, because that's the answer any psychiatrist with half a brain would give regardless of whether or not they even recognized the person. They cannot confirm or deny. A neutral answer is the only thing that a psychiatrist—or any physician—should ever give.
  • Law & Order: UK: The detectives have arrived at a junkyard to look for a murder suspect. The supervisor denies that he's there. Suspecting otherwise, DS Devlin very casually calls out, "Oi, Freddy!" Sure enough, the "Freddy" in question looks up, then further confirms his identity by bolting when he sees the cops.
  • In one episode of Law & Order: Criminal Intent, Goren and Eames are trying to find the missing daughter of a family annihilator. They suspect that he hadn't actually killed her yet (because she had apparently been tied up and transported elsewhere, while this killer tended to kill his victims wherever they happened to be), but they can't be sure, so Goren asks the killer why he spared his daughter's life. The killer actually recognizes the trap and tries to avoid it by giving an ambiguous response, but Goren knows that if he had killed her, he would have just said outright that she was dead; the fact that he's hedging could only mean that the daughter is in fact still alive.
  Killer: You don't know that she's alive.
  Goren: Now I do.
• Letterkenny: Katy uses this tactic to get the hockey players to admit that they were cheating on her before she was cheating on them. Twice.
• Frequently done by Cal Lightman in Lie to Me to get the criminal-of-the-week to reveal themselves. One case involved a woman in the US Army claiming to have been repeatedly raped by her commanding officer. While Cal quickly figures out that she's lying, she actually did that for her friend whom that same officer was raping. He would threaten to put her in the front vehicle of a convoy, which is often the first to be hit in an ambush or by a mine. When questioning him in front of the base commander, Cal pushes the point until the officer unintentionally yells out that he never puts her in the first vehicle. The base commander realizes the implications of this: he doesn't put her in the first vehicle, even though he's supposed to as part of the normal rotation, because she's sleeping with him. The base commander calls the MPs to take the officer away.
• In the Lost episode "The Cost of Living", Jack has seen x-rays and believes they are Ben's, so he questions him about symptoms. Ben's reaction gives him away. Later he asks Juliet why she told Jack about his tumor, to which Juliet replies that she didn't; Ben did.
• In an episode of Lou Grant, newspaper reporter Billie Newman attempts to break the ice with a street youth she is trying to befriend by using this ploy, stating something she suspects about him as if it were fact, and when he asks her in astonishment how she knew that, she replies with the trope namer, "You just told me...it's an old reporter's trick." These words come back to haunt her however, when they are smugly quoted by the same teenager after he tricks her into giving away some vital information using her own ploy.
• In Mako Mermaids: An H₂O Adventure, Evie attempts to bluff Cam into telling her Zac's secret by announcing that he finally told her, and that she completely understands. It sorta works, with Cam showing relief and even outright telling her that Zac should have told her in the first place, which at least confirms that Zac has a secret to hide. However, Evie legitimately has no idea whatsoever what Zac's secret is, and accidentally gives the bluff away by saying it's something everyone has to go through. Since Cam knows full well that the secret in question is suddenly gaining merman powers, he doesn't buy it past that.
• In the M*A*S*H episode "Out of sight, out of mind", Hawkeye gets temporarily blinded by an exploding camp stove; and goes to sit in a nurses' tent for a while as he's at loose ends. One of them is cautious about undressing with a man in the tent, even thought he can't see her. At the end, after he is cured, he wraps his head back up again and goes back into the same tent, tells them he has had a relapse, and suggests that they would be perfectly safe undressing. One of them promptly tosses a mug at him, which he catches perfectly; and they throw him out of the tent with some alacrity.
  • An earlier episode had a rash of thefts occur in the 4077th, with the stolen articles found in Hawkeye's footlocker. To catch the real thief, Hawkeye stages a conversation with Henry to be broadcast over the PA, saying the equipment to get fingerprints off the stolen items is en route. The items are subsequently stolen from Henry's desk. Hawkeye then gathers all the "suspects" (everyone who had something stolen, or simply held a grudge against Hawkeye) to the mess hall, where he says he treated the stolen goods with chemical that would turn the thief's fingernails blue. The culprit turns out to be Ho-jon, who was going to sell the stolen goods on the black market to get money to smuggle his family out of Korea. He gives himself away by hiding his hands under the table when Hawkeye makes the "reveal".
• The Mentalist:
  • Patrick Jane and the team encounter a hooker who seems to know only Chinese, but when Jane comments on an imaginary hideous thing on her shoulder, she nearly jumps out of her skin. Busted.
  • There was also a similar thing when they suspected a dead guy was a member of a fancy private club. Jane just waltzes in, calm and confident, then (paraphrased):
    Receptionist: Sir? This is a private club, I'm afraid you...
    Jane: Oh, that's fine, I'm a member. My name is <dead guy's name>.
    A man sitting nearby approaches
    Man: Excuse me? I happen to know Mr. <dead guy's name>, and you are not him.
    Jane: Thank you, for confirming that he was a member.
• In an early episode of Merlin, Gaius is certain Merlin is a wizard, but wants to see it for himself. He "accidentally" knocks a pitcher of water off the table, causing Merlin to react by using magic to freeze the pitcher in mid-air. When Merlin realizes what he's done (as he was explicitly warned not to use magic in Camelot, where it is banned), he releases the pitcher, but not before Gaius points out that stunts like that would blow his cover very quickly.
• The bad guys tried this quite frequently on Mission: Impossible, but one notable case had a gangster see Rollin (playing a deaf waiter) react slightly when a large amount of money was mentioned. In order to test the him, the gangster fires off a revolver next to his ear. Rollin fakes not hearing it, passes the test, and reacts in agony at the pain when he gets out of sight. (It's worth noting that the pain experienced from loud noises is because of the concussive force striking your ear drum, so while a deaf person may not be able to hear the sound, they are certainly capable of feeling it, and the associated pain.)
  • Another episode had the team infiltrating a camp where foreign agents were being trained to pass as Americans. Rollin intentionally blows one such test to prove he's a "genuine" newbie who wouldn't know how Americans would act.
  • And in yet another, he catches a glass vase abruptly tossed at him by a foreign spy, who knows the spy Rollin is impersonating is left handed.
• Monk:
  • In "Mr. Monk and the Sleeping Suspect", the identity of a mail bomber is confirmed when he panics at the sight of someone opening one of his custom-made packages. He shouldn't have known about the bombings because he had been in a coma when they took place. (If you're curious about how he managed to set off the bombings while in a coma, watch the episode in full).
  • In another episode, Monk cleared Willie Nelson's name by proving that the other suspect wasn't blind (or at least, not completely blind)—he had a streaker run past her, and she reacted.
  • In yet another episode, the murderer had to make sure that his wife's corpse was found without revealing that he had killed her, so he staged it to look like a psychic had found the body. Monk trapped him by getting the psychic to accuse him of murder, thus forcing him to discredit her—and he helpfully though inadvertently confessed in the process.
• The Nanny: Fran does one of these to C.C. in "Where's the Pearls?" when she guesses that she and Maxwell are trying to keep her away from a celebrity. She's right: it's Elizabeth Taylor!
• Used once on NCIS when they had a suspect who refused to tell them who he was or which country he came from. They had Ziva speak to him in all the different languages she speaks, and when he stared blankly at her the whole time except for a visible reaction when she spoke Russian, they knew that he was from Russia.
  • In another episode, a young woman is arrested for practicing medicine without a license for providing first aid to car crash victims. Gibbs notices her medical bag and on a hunch, calls out "Corpsman!". She instantly snaps to attention, revealing her military status.
• NCIS: Los Angeles: Deeks does this to Kensi by commenting he didn't see a phobia she'd just mentioned on her online dating profile.
  Kensi: How did you know that I...
  Deeks: I do now!
• The second season of Oz begins in the aftermath of a prison riot, with an investigator trying to find out who shot and wounded McManus, a high-ranking prison administrator, and how a prisoner named Scott Ross was shot multiple times and killed by a weapon that was reported missing from the prison's equivalent of a SWAT team, a weapon which later reappeared in the prison armory without explanation. Near the end of the episode, the investigator confronts McManus and explains a crucial fact McManus had left out of his prior account, which would lead to revealing the identity of the person who killed Ross. After a long period of silence, McManus grudgingly asks "Who told you that?" Three guesses what the response is.
• An episode of Poirot features this exchange:
  Poirot: Tell me, you have lived in New Zealand?
  Suspect: [Astonished] However did you discover that? Mind you, it is known.
  Poirot: Is it? I have tried numerous ways to discover it without success.
  [The suspect looks pissed off and cornered.]
• Subverted in an episode of Quantum Leap in which Sam leaps into the body of a blind musician, and must pretend to be blind even though he's kept his sight. The mother of the leapee's girlfriend walks in on him reading information from a box of dog treats and (not unreasonably) concludes that the leapee must have been a sighted fraud all along. When she tries to out him by flicking a lighter in front of his face, however, he genuinely can't see it because he's just been temporarily blinded by a camera flash.
• Rome:
  • This happens in a manhunt for Cleopatra's son.
    Officer: [Latin] Right, be off with you. [turns away] [Egyptian] Please bless us with your forgiveness, sacred majesty.
    "Greek slave": [Egyptian] Granted, mortal.
    [beat]
    [fight scene]
  • In this same series, Atia uses this tactic to expose Octavia's relationship with Agrippa.
• In Scrubs, Turk eventually tricks Carla's brother into speaking English in front of her (she thought he only knew Spanish) by saying explicitly sexual things about Carla in front of him.
  • Dr. Cox does the opposite by insulting Turk in Spanish (which Turk learned in secret from Carla).
• Ricky does this to Ben in The Secret Life of the American Teenager when asking Ben if he had been to see Adrian.
• Elaine pulls this trick on George in "The Red Dot" episode of Seinfeld.
  Elaine: Hey, George. Did you buy that sweater, knowing the red dot was on it because you could get it at a discount? Jerry told me that you did.
  George: [turning to Jerry] You told her?! How could you tell her? What kind of friend are you?
  Jerry: I didn't tell her, you stupid idiot! She tricked you!
  • She tries it again on Jerry in that same episode, but he sees through it.
    Elaine: Did you leave that drink by Dick on purpose, knowing he's an alcoholic?
    Jerry: Absolutely not.
    Elaine: [bluffing] Really? Because George said that you did.
    Jerry: Nice try.
  • A nice subversion in this case, as Jerry is telling the truth.
• Sherlock: Holmes does this on numerous occasions, notably to get Irene Adler to reflexively glance at the cabinet where the compromising photos she took are in "A Scandal in Belgravia".
  • In another episode, the great detective questions a woman by making deliberately incorrect guesses. The woman is eager to humiliate Sherlock and smugly corrects him each time, after which he thanks her for volunteering the information he was looking for.
• In one episode of the sketch show Smack the Pony, two women and one man are being held hostage alone in a room somewhere. One of the women tells the others that her name is some male one. This puzzles the second woman and she keeps asking for explanations for it, but the other just maintains it just is that way. Eventually we see the second woman whispering the other various female names while she sleeps, until she reacts to one and has to admit that was her real name all along; she was just fooling the others as a joke.
• Stargate SG-1:
  • This trope is used and parodied in "1969". The team is stranded in a top-secret Air Force facility in 1969, and are suspected of being spies. An Air Force interrogator comes in:
    Airman: Вы советские шпионы? (Vy sovetskie shpiony?)
    Daniel: Нет! (Nyet!)
    O'Neill: Daniel?
    Daniel: He just asked if we were Soviet spies, I...
    O'Neill: [glares]
    Daniel: Um.
  • In another episode, when preparing to give the Aschen some Stargate codes, Samantha Carter then asks one of the Aschen what a particular word means. The Aschen, not realizing the repercussions of what would happen, simply answered "sterility," in essence admitting that the drug they were giving the Tau'ri would actually give them sterility, making quite clear of the Aschen's ill-intentions towards Earth.
• In Star Trek: Deep Space Nine, Dr Bashir is up for a major medical award. He insists that there is no chance of victory for him, and so he does not wish to discuss it.
  Odo: In that case, why are you working on your acceptance speech?
  Bashir: (Hides pad) How did you know?
  Odo: (smugly) Just a guess.
  • Another occurrence appears in "The Ascent", in which Odo is delighted to receive orders to arrest Quark and bring him to a Federation court, but isn't told why. He drops several clues to Quark that he does know, such as "Oh, I think you KNOW why I'm arresting you," trying to invoke this trope. It works, but not in time to prevent the Orion Syndicate from trying to blow up their ship, leaving them stranded on an uninhabitable planet. It turns out Quark wasn't even being charged with a crime, but rather subpoenaed as a reluctant/unwilling witness against the Syndicate, which is why they're after him. Quark and Odo are both incensed at each other when they discover the bomb which was planted on the shuttlecraft. Quark is mad at Odo for trying to invoke this trope on him, while Odo defensively lashes out that if Quark had just spilled the beans they'd have had a lot more security in place for their trip.
• From an episode of Suits:
  Harvey: Did you go see Joy, after I told you not to?
  Mike: How did you know?
  Harvey: I didn't. Until now.
• That '70s Show does this in combination with a Continuity Nod from an earlier episode.
  Red: You lied when you said you weren't taking the car out of town.
  Eric: Wait, you knew about that?
  Red: I do now.
• In the Two and a Half Men episode "Aye Aye, Captain Douche", Berta uses this to deduce one of the possible reasons Charlie was sleeping on the couch:
  Berta: Did [Chelsea] find the Polaroids?
  Charlie: How did you know about the Polaroids?
  Berta: I didn't. You just told me.
• Used by Elena in The Vampire Diaries. It doesn't seem like a trick, exactly, if you watch it.
  Elena: I'm asking you.
  John: That doesn't mean anything to me.
  Elena: As my father, it should.
  John: How did you know?
  Elena: I wasn't sure, until now.
• Vera: In "Dark Road", Vera confronts a suspect and asks him why his thumbprint was found on a broken glass at the crime scene. After he admits being there, he asks how they knew it was his thumbprint, Vera replies:
  I didn't, pet, till just now.
• This priceless exchange from Will & Grace:
  Jack: Oh. Oh, I know. I know what this is. Will told me everything. Grace, you really did it this time!
  Grace: (to Will) You told him I slept with Rob?!
  Will: Uh, no.
  Jack: Works every time.

Roleplays

• In Part I of The Chaos Zone, King K. Rool pulls this on the narrator when he prepares to track down whoever broke the Crystal Coconut.
  K. Rool: I'm going to find the one who broke the Crystal Coconut and ruined my perfect scheme... And clobber them into dust!
  Narrator: The Gangplank Galleon II sails off to find Dark Elf! ...Wait, how will he even know who to find?
  K. Rool: Because you just told me, narration boy!
  Narrator: ...I should just learn to keep my mouth shut sometimes.

Video Games

• Piros the 3rd of .hack//G.U. claims that Haseo doesn't deserve to know his name... then introduces himself in an over-the-top manner. This trope's name is Haseo's exact response to this.
• On the final day of Golden Playhouse mode in Catherine, Vincent confronts Boss, the barkeep at the Stray Sheep, about the fact that he was the only other person able to see Catherine, and accidentally gets Boss to blab about his involvement in the reoccurring nightmares Vincent and the other patrons have been having.
• Used in Fire Emblem: Radiant Dawn:
  • Heather, a small-time thief, confronts Yeardley, a general working on Duke Ludveck's orders, about his attempts to get the townspeople of Crimea to revolt against Elincia.
    Heather: So! You're the ones sent by Ludveck of Felirae?! You've been stirring up these little revolts all over the place!
    Yeardley: What?! How did you know?!
    Heather: I see things here and there. But half of it was just a guess! ...Judging by your reaction, though, it seems I was right.
  • Later on, when Marcia confronts her useless brother Makalov as he tries to avoid fighting Imperial Army troops:
    Marcia: ...I think I see. You owe them money, don't you? Isn't that the real reason why you don't want to see them, cheese breath?
    Makalov: W-when did you learn to read minds like the herons!?
    Marcia: I can't, you spineless sea cucumber! It's just so typical of you that I guessed!
• In Fire Emblem: Three Houses, Linhardt uses this on Lysithea to confirm his suspicion that she has two Crests.
  Lysithea: You haven't told anyone, have you?
  Linhardt: Of course not. If someone else were to learn you have two Crests, I might lose you as a test subject.
  Lysithea: Ah! Please stop talking so loudly! So what if I have two Crests? If you insist on speaking of it, please do so quietly.
  Linhardt: My intuition was correct! You do have two Crests.
  Lysithea: Wait - What?! Did you just trick me?
  Linhardt: "Trick" is such a strong word. I think of it as testing a hypothesis. The truth is I simply made an educated guess.
• In Kingdom Hearts: Chain of Memories, Axel is sent to Castle Oblivion because Marluxia and Larxene are suspected of plotting against the Organization. About halfway through the game, Axel chats with Larxene about the plan they have for Sora as Larxene heads down to meet Sora.
  Axel: Don't forget. Sora is the key. We need him if we're going to take over the Organization.
  Larxene: I know that you're in on it too, but keep it under your hood. At least until the time is right.
  Axel: [after Larxene leaves the room] You would have been wise to do the same, Larxene.
• In the third case of Phoenix Wright: Ace Attorney – Trials and Tribulations, Phoenix gets the real killer to incriminate himself by presenting a bottle of the victim's ear medicine, and claiming that it contained the poison used to kill the victim. This is a Blatant Lie to anyone who had been watching the trial, as the real poison bottle had already been presented. The killer had not been watching the trial, nevertheless he proceeds to call Phoenix an idiot and gives an accurate description of the real poison bottle, proving that he is the killer.
• In Shinrai: Broken Beyond Despair, this is how Taiko learns about Runa being in love with Hiro.
  Rie: Runa's gonna die of embarrassment if even more peeps know...
  Taiko: That she's in love with Hiro?
  Rie: Eh!? Y-You knew about it??
  Taiko: Oh, so she is?
  Rie: Wait, what? Whaaat?? You tricked me!!
  Taiko: Ah, come on, it wasn't too hard to put two and two together from what you told me just now. You just confirmed my suspicion.
• In Sonic Adventure 2, Dr. Eggman uses this ploy to confirm his guess that one of the two identical-looking Chaos Emeralds was a fake, having looked at readings from the 2 separate Emeralds at his pyramid base earlier. (Not that it's very likely Tails would knowingly give Eggman the real one if he had a fake one as well.) Tails' facial expression after it seals the deal; it's a mixture of Oh, Crap! and Not Bad.
  Eggman: You thought you could trick me with that fake Emerald, didn't you?
  Tails: So... how did you know it wasn't the real one?
  Sonic: [cutting him off] TAILS!
  Eggman: Hah! Because you just TOLD me, fox-boy!
  Tails: [eyes widen in realization]
• In Star Ocean: Till the End of Time, Fayt tricks Cliff into revealing that he has been in contact with Mirage and even gets Cliff to tell him what their conversation was about by simply asking "So what did Mirage say?" Cliff is pretty impressed by his craftiness.
• In Suikoden, Viktor uses this on Tesla in order to recruit him since Tesla just wants to live a quite and simple life and pretends to be Albert Onyx. The party already learned that he will pretend to be Albert from Kimberly before visiting him.
  Viktor: You're Tesla, the Scrivener, right?
  Albert: Goodness, no. My name is Albert Onyx. My people have lived here for generations.
  Viktor: Really? Then what is your mother's name?
  Albert: Ummm, her name is Marianne Onyx.
  Viktor: And your father?
  Albert: I believe it was... Ah... Allen Onyx.
  Viktor: Grandmother!
  Albert: Uhh... let's see... Leah Onyx.
  Viktor: Hey Tesla.
  Albert: Yes?
  Albert: .............!
  Albert: I mean... that's not my name, Tesla.
  Viktor: Do you give up?
  Tesla: All right. Mathiu wants me, right? I prefer to lead a quiet life.
  Viktor: Stop yapping and get ready to leave.
  Tesla: O-OK. My god, how unlucky I am.
  Tesla: Led back into a life of crime. *Tesla joins*
• In Uncharted 3: Drake's Deception, Marlowe tells Nate Drake that she knows where Ubar is because 'you told us, Nathan' while he was under the influence of a Truth Serum.
• Xenoblade Chronicles 2: After being captured, Nia is so sure they're after the names of the crew she was with previously that she's a little poleaxed when the Inquisitor questioning her reveals she's more interested in Nia's more recent traveling companions.
  Nia: Rex and Pyra?
  Morag: [amused] Well, that was easy.
  Nia: (Dammit!)

Visual Novels

• My Little Investigations: At one point, Twilight realizes that Apple Bloom is hiding something. The filly tries denying, but ends up only confirming Twilight's suspicions.
  Apple Bloom (annoyed): Why would you think I'm not telling you something, huh?
  Twilight (equally annoyed, thinking): Because you just told me that you're not.

Web Animation

• From the first Metal Gear Awesome:
  Psycho Mantis: You like men!
  Snake: You can see into my mind?
  Psycho Mantis: No.
  Snake: Fuck.
• This is how the Engineer was outed as the killer by the Demoman in Heavy is Dead. Of course, Demoman's accusation was, according to him, just a joke.

Webcomics

• 8-Bit Theater:
  • Used by Thief figuring out he doesn't owe his life to anyone after all.
    Crow: How did you find out?
    Thief: I only suspected it until you confirmed it for me just now.
  • And in an earlier strip:
    Red Mage: Wait, we figured that out?
    Thief: No one can say we don't know it now. That's close enough, really.
• How Cohen in But I'm a Cat Person confirms the identity of Cybele's Master.
• Cleverly done in Dan and Mab's Furry Adventures:
  Bigs: (thinks) If you are trying to read my mind I swear I will deck you.
  Dan: Huh? How would you know that I—
  Pow!
• Dumbing of Age has Mike use it successfully on Sal:
  Sal: [after Mike suggests she seduced a teacher] Mike, you been Tailin' me? What do you know?
  Mike: Nothing. But cast enough lures, you eventually land a fish.
• In this Everyday Heroes episode, Mr. Mighty finds out about a planned crime. It works so well, he tries it again on the next page.
• In Exterminatus Now Steve effortlessly got Virus to confirm that the group visiting Cesspool is from Inquisition.
• How Cake Girl in Gloomverse figures out the origin of Harold's partial-invisibility.
• In Girl Genius a mostly time-stuck Castle Heterodyne keeps hinting that it knows the "technician" accompanying Higgs is Gil but it doesn't know until he tells it to stop messing around since it knows who he is. He looks a bit unsettled when it informs him:
  Gil: Cut it out. You know it's me.
  Castle: I certainly do now. Very well. We shall end this amusing charade.
• This moment in Homestuck where Vriska is irritated that John found out her name:
  AG: I am very pissed off that you figured out my name.
  EB: well, i didn't know it was your name for sure until you just told me now.
  EB: so, haha.
  AG: Dammit!
• In the "Cliffhangers" theme of Irregular Webcomic!, Colonel Haken uses the "Once again, Dr Jones, we see there is nothing you possess which I cannot take away" line. Despite the attempts of his father and grandfather to shush him, Montana Jones replies "But ... what do the Nazis want with the Palladium of Troy? And how did you even know what we were after?!" and Haken smugly concludes "And again, we see there is nothing you can try to find which I cannot find out you are trying to find."
• In this Krakow comic, Canadian rap sensation Snow tricks one of the characters into admitting that he altered the lyrics while singing one of Snow's songs.
  Case: But...but...How did you know that?
  Snow: I only had suspicions, but you just confirmed them!
• Narbonic:
  • During the D-Con Story Arc:
    Helen: You know I'm not "Dave Pretorius." There's no such man. You know I'm really your own daughter in disguise. You know I infiltrated D-Con to crack the Dave Conspiracy, having no idea you'd already done it! ...And you didn't actually know any of this until I voluntarily told you, did you?
    Dr. Narbon: I'm such a great mother.
  • In a later strip, Helen tells Dave that they need to talk:
    Dave: Uh oh. Is this about the sentient meme that took over the net in Blue Sector and keeps threatening to vaporize us via spy satellite?
    Helen: No! This isn't about the sentient meme! I didn't even know there was a sentient meme!
    Dave: Oh... good.
    Helen: On second thought, let's make this about the sentient meme.
    Dave: It was supposed to be a Serenity personality quiz! I meant no harm!
• A priest in Nukees confirms Gav is a lapsed Catholic by saying "peace be with you" as he leaves, getting an automatic "and also with you."
• A creative application of the trope occurred in Rip And Teri. Agent XI knows Rip has infiltrated a TV studio in disguise. A few days earlier, Rip had encountered XI in a janitor uniform, so XI stations himself inside the studio in the same uniform. Rip's startled reaction to seeing the same "janitor" he fought earlier gives him away.
• Schlock Mercenary: the 'NUSPI' (No User-Serviceable Parts Inside) is actually created on the same principles as the long-gun, and Sorlie is able to figure it out with barely a glance. She then confirms it.
  Murtaugh: Your engineering skills are way above your pay grade.
  Sorlie: Actually, I only put it together a minute ago. Then I guessed, and you confirmed it.
  Flinders: Your intel skills are way above your pay grade.
• A truly astounding example in Scenes from a Multiverse:
  Sam Greely, Crab Detective: You were running a variant of the Benton Murder Scam, murdering crabs for cheap construction materials. Lucy put two and two together. She was a bright dame. She blackmailed you for a million smackers and the legendary black pearl of Bahbs'ye Runkul, which you wear on a chain under your shirt. But you didn't take orders from no dame, so you hired a hitman to dress as a clown and take her out. She never would have suspected a clown.
  Perp: How... how did you know.
  Sam: I didn't. Until you confirmed it for me just now.
• Servants of the Imperium: Used by Aki in strip #181: "Intelligence".
• Jake, the usual dumb friend, from Slightly Damned, pulls this one on Rhea Snaketail to get her to admit to having been previously murdered.
  • Over 400 pages later Rhea get's her own back with a similar trick:
  Rhea: Don't be upset. Ramirez is still out there for you, right?
  Jake: WHO TOLD YOU I HAD A CRUSH ON RAMIREZ?!?
  Rhea: (Incredibly smug face) You did. Just now.
• In Two Evil Scientists, Eggman Nega invokes it here when he's confronting his ancestor

Web Original

• In High Fidelity, after Simon tells Sandra that he's going to Europe to find Jeremy:
  Sandra: I could believe this stupid shit from Mike, but I never thought I'd catch you thinking with your dick!
  Simon: ...What?
  Sandra: You heard me!
  Simon: Christ, does everyone know about it by now? How long have you known?
  Sandra: Known for sure? For about— [checks watch] —ten seconds.
  Simon: Oh Jesus, I walked right into that, didn't I?
• From Not Always Right, "Should Just Slink on Out of There": Customers try to exchange a completely mangled Slinky, with an obviously bogus story that it was broken in its original package. There's an escalator just outside the store, so the attendant makes an educated guess:
  Me: So guys. You’re telling me that you DIDN’T try to push this slinky down the step escalators?
  Customer: Uh... Uh... So you saw that, huh?
  Me: No, but now you’ve admitted it, we can’t provide you with a new one for something that’s not our fault. Have a nice day!

Web Videos

• French Baguette Intelligence: In Is Lightning McQueen trans?, FC manages to get one out of Bowl by accident.
  Faux Cares: Or maybe he lost them gambling; like that one lad I know who lost his testicle in Monaco.
  Bowl: Dude! I told you that in confidence!
• In the new season of The Guild, this is how Codex admits to sleeping with Fawkes.

Western Animation

• In the American Dad! episode "The Fellow Traveler," CIA agent Avery Bullock (Sr.) catches the alien, Roger, who was in disguise as an angel. Bullock said he knew Roger wasn't an angel, causing Roger to lament that it was because his costume lacked wings. This confirms Bullock's suspicion, as he wasn't 100% certain until Roger admitted he was wearing a disguise.
• Azula in Avatar: The Last Airbender uses this to trick Zuko out, not about his identity, but about visiting his Uncle Iroh.
  Azula: So, I hear you've been to visit your Uncle Fatso in the prison tower.
  Zuko: That guard told you!
  Azula: No. You did. Just now.
• In Daria, a Dream Sequence that parodies Murder, She Wrote has Daria investigating the murder of Kevin, that she's been framed for. She says that she coated her locker (where the murder weapon was planted) with a clear paint that changes color over time, and the hands of whoever was in her locker would be turning pink any minute. Three suspects check their hands, then she says she made the whole thing up since only the guilty party would look.
• Doug: In "Doug Gets His Wish", a douchebag student named Willy claims his teacher is incompetent and tries to get her fired. In front of an assembly, Doug asks Willy questions about classic novels, mangling the details along the way. Willy smugly corrects Doug at every turn... but Doug points out that he and Willy learned all of that stuff in the teacher's class, so she has to be decent at her job. Willy has no choice but to drop his suit.
• Parodied in Invader Zim episode "Mortos der Soulstealer":
  Dib: Zim! I don't know what your plan is, but I'm gonna stop it!
  Zim: I am infecting this city with genetically enhanced vermin, but you'll never know!
  Dib: You just told me.
  Zim: [beat] You're LYING!
• In Iron Man: Armored Adventures, Pepper has a hunch that Tony Stark is Iron Man, so she confronts him about it and he casually asks how she figured it out. You just told me. Though in his defense she did give him some good reasons that he believed she already knew, she was practically just confirming it by this point.
• Total Drama Revenge of the Island: Scott uses this to trick Cameron into revealing Mike's multiple personalities.
  Scott: Mike wanted me to let you know that he's thankful you're helping him out with his "problem".
  Cameron: He told you about his Multiple Personality Disorder?
  Scott: No. But you just did.
• In Transformers: Prime, when Arcee has Starscream in her custody, she mentions how Airachnid offlined her partner. Starscream loudly complains about Airachnid "taking credit for that, too". When Arcee mentions she's talking about Tailgate, Starscream asks "who's Tailgate", tipping her off that it was he who terminated Cliffjumper. Unusual for this trope, Arcee didn't have any suspicions toward Starscream until he said he didn't know who Tailgate was: she'd thought that Cliffjumper was killed by some random Vehicons.

Real Life

• A shibboleth is a word, sound, or custom that a person unfamiliar with its significance may not pronounce or perform correctly relative to those who are familiar with it. It is used to identify foreigners or those who do not belong to a particular class or group of people. It also refers to features of language, and particularly to a word or phrase whose pronunciation identifies a speaker as belonging to a particular group.
  • The Other Wiki gives us a list.
  • The word's origins are in The Bible (Judges 12:5-6), where the word was used as a test to reveal whether someone had a regional accent. The Ephriamites would pronounce it as "sibboleth," thus giving away the fact that they were enemy agents. That makes this one Older Than Feudalism.
  • Dominican dictator Rafael Trujillo conducted a brutal massacre of undocumented Haitian settlers along the Dominican-Haitian border. The action is known as the Parsley Massacre. Suspects not fluent in Spanish either did not know or could not properly pronounce the Spanish word 'perejil' (parsley). The pronunciation of the word by Haitian citizens tended to be with a non-rotative r and an omission of the 'l' at the end of the word.
• Shouting "Attention!" is one method of revealing if someone has military training (an FBI agent did this while interrogating a suspect in the 1998 Nairobi bombing). Shouting "Achtung!" unexpectedly was used among Allied prisoners of war to uncover German infiltrators.
• To tell if someone speaks a language or not, police often ask them to say what color different words are (like the word "red" written in green ink). People who speak the language will take far longer. This is because this is the Stroop Test, a psychology tool in which taking longer is normal, under normal conditions.
• A Russian proverbial story tells about a guy who spots a pickpocket in the market. Nobody else sees it, though, so the quick-witted fellow points in the thief's general direction and shouts: "That thief's hat is on fire!" The crook instinctively grabs his headgear...
• Very similarly, in a Serbian folk tale, St. Sava (the man that established the Serbian Orthodox Church) was asked to use his wisdom to find a thief in a crowd. He replied with "Oh, that's easy. It's the guy with the bee on his hat!" pointing out into the crowd's general direction. Of course, the guy waves his hand to chase off the (nonexistent) bee, and gets caught.
• Pickpockets use this to find people's wallets.
  • A lateral thinking puzzle asks how police putting up signs warning about pickpockets actually helps the thieves. The solution is that pickpockets hang around the signs. When people see the notices, they automatically check their valuables to make sure they haven't been stolen, showing the thieves exactly where they keep them.
  • One TV show about scams showed that thieves sometimes take advantage of this and put up the signs themselves!
  • An old trick among pickpockets working in groups is to have one person turn to a friend and (loudly) proclaim "Somebody stole my wallet!" The marks nearby instantly will pat their own wallets, broadcasting the location of their valuables.
  • Even more subtly. Most people will subconsciously check their wallet if bumped into in a crowded place. Pickpockets use this to learn which pocket their mark keeps it in before making their move.
• Undercover police officers usually use their own first name to avoid this.
• To avoid this, while agents were in training they would be woken up by instructors in the middle of the night and asked things like "what is your mother's maiden name". The other point was so they would know their cover story so well it may as well have been their own life.
• A member of Allied intelligence in World War II thought agents were captured and impersonated, so at the end of one of the messages he sent H.H. (for Heil Hitler). The message he got back from the 'agents' also ended in H.H.
• A preteen/teenager joke in Brazil is saying "The hands of whoever just farted are yellow". Whoever looks...
• A similar joke in the United States is to say "Did you know frequent masturbation gives you hairy knuckles?" and then mock whoever takes a moment to check.
• This is why government authorities who are supposed to keep a secret are supposed to use the stock line "I can neither confirm nor deny that" when asked any question vaguely related to secret matters, even if it's not a secret they know or is completely off base. It stops the pattern of "no", "I can't answer that", and "I don't even know what you're talking about" from revealing information.
• Commonly used by parents to trick young children into outing themselves on lies. One variant has the parent use "magic powder", or some facsimile thereof, to supposedly make a child's ears turn colours whenever they lie. Not difficult to spot fibs when the child in question starts conspicuously covering their ears.
  • There's an old story with a non-verbal variation. A hotel's guest had valuables stolen by another guest at the hotel. They call in a wise man who hands out sticks, each of the same length, to the guests. He says that they're magic, and the stick given to the thief will grow a certain amount in the night. The guests handed their sticks to the man the next morning, and the thief was the one with the shortest stick, as he had trimmed it to disguise its growth.
  • A story told about the mathematician John Napier says that he believed one of his servants was stealing from him, so he declared that they all had to enter a dark room and touch his rooster (not a euphemism) who would crow if it felt the touch of a dishonest man. Since people were rather fuzzy on the difference between scientist and sorcerer at the time, and it was widely rumoured the rooster was his familiar, this sounded plausible. Afterwards, he explained that the rooster was covered in coal dust, and the thief was the man with clean hands.
  • Yet another variant involves a wise man setting up a box, backing a donkey against a hole cut in it, and telling the suspects to enter the box and pull on the donkey's tail. The donkey would only bray for the thief. Of course, the "tail" the people were pulling in the box wasn't actually the donkey's tail, but it was coated in oil, so the thief could be caught dirty-handed (or clean-handed, as the case may be).
• This is sometimes used a part of Cold Reading and similar trickery. For example: a Phony Psychic, magician, etc might say something like "I see something having to do with the letter D," and the client might say something like "My sister's name is Darci! How did you know that?" Well, they didn't, they just made a vague guess and you supplied the information. Furthermore, considering there are only 26 letters in the alphabet, and D is a fairly common one, it would be more unlikely if the average person couldn't find some kind of connection to it, especially if they already want to believe the person has Psychic Powers.

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