Tongue-Tied

Oh, I'm begging on my knees
Sweet, sweet darling listen please
Understand me when I say:
Be-durble-diggle-doggle-diggle-doddle-diddle-day

—Red Dwarf, The Tongue Tied Song

A Tongue-Tied character has some extremely important knowledge, and just Cannot Spit It Out... quite literally.

Sometimes a victim has to be kept quiet about what exactly has happened to him, or he may have learned a secret that someone doesn't want him to share. He can be threatened or encouraged to lie, but this is unreliable. Some villains attempt elaborate brainwashing or Laser-Guided Amnesia, but these options are all startlingly reversible. In light of this, the occasional magically-inclined Villains will place a Curse on his victim that also leaves the victim Tongue-Tied.

He isn't silenced completely; the Curse doesn't ordinarily prevent him from speaking or casting magic. The cursed individual just becomes unable to communicate a certain piece of information, like "I'm not really a frog, I'm a transformed prince!" or "I know where the villain's hideout is!" or "I'm under a curse!" If he tries to talk about this particular subject, he may be unable to speak at all, it may all come out as gibberish, or he may be magically forced to give a cover story in place of the truth he desperately wants to tell. In fact, this is often a secondary effect of a Baleful Polymorph curse, preventing the transformed character from getting help for his condition.

This "curse" is usually magical in nature, since the character will find himself unable to share the secret regardless of how badly he wants or needs to, but mental conditioning can sometimes be used to similar effect.

A Tongue-Tied character may occasionally function as The Speechless, and his problem is very similar to the character who Cannot Spit It Out. Compare Keeping Secrets Sucks. Tongue-Twister is the mundane equivalent.

Examples of Tongue-Tied include:

Anime and Manga

In Howl's Moving Castle, Sophie is unable to tell anyone that the Witch of the Wastes has turned her into an old woman.
- This is an exact example in the movie, but not in the book. In the book it is a subversion, because almost everyone knows about it, and has tried to lift the spell from her.
- A similar case applies to the connection between Calcifer and Howl; he's unable to reveal what it is, but Sophie's allowed to guess or figure it out on her own.
This is the effect of the Talking Heads stand from JoJo's Bizarre Adventure Part 5, however the person affected by it is entirely incapable of telling the truth.
In Alice 19th, Mayura magically "forbids" Alice to tell Kyo about her feelings for him - and about the spell she uses to do this.
Suzumiya Haruhi: Mikuru's time-travel discussions tend to go along the lines of "I was so shocked that I tried to use [classified information]... and then [classified information]..."
Sai of Naruto and all other members of Root had seals placed on their tongues to keep them from betraying any of Danzo's information. However, since Danzo is now dead, those seals are gone.
Ahiru in Princess Tutu cannot tell Mytho that she loves him, or else she will disappear in a speck of light.

Comic Books

Baron Mordo does this to Stephen Strange in order to prevent the stranger from telling the Ancient One of Mordo's treachery. It doesn't prevent Dr. Strange from asking to learn magic himself, however, and once he does so the Ancient One immediately releases him from the spell admitting he knew about it all along.
Poison Ivy did this to the Wayne Foundation board members in one Batman story arc. She used mind control to get them to sign over the Foundation's assets to her and gave them a post-hypnotic suggestion that prevented them from telling anyone what had happened.
In Mighty Avengers, Cassie learns that "Wanda" is actually Loki in disguise, but he curses her into not telling anyone.

Film

Several Abbott and Costello films have Costello needed to impart some important information, usually that the movie's villain is nearby. However, while he mimes speaking the words, he's so scared that he literally cannot make any kind of audible sound.
Perhaps the reverse of this trope, in the movie Liar Liar; not only does a birthday wish prevent Jim Carrey from telling lies, he also cannot withhold the truth (lying by omission) or even ask a question that he knows will be answered with a lie.

Literature

In Emperor Mage, Daine is prevented from telling anyone that there's a goddess running around causing havoc.
In Ella Enchanted, Ella (who has been given the "gift" of obedience), is ordered to tell no one about this "gift," so of course, she is forced to obey.
In the third book of Lynn Flewelling's TamÃr Trilogy, the evil wizard puts one of these spells on the girl he forces the prince to marry, so she can't tell the prince of the wizard's machinations, including the fact that she's only a virgin because the wizard magically recreated her hymen.
The Summer Lady had this once in Jim Butcher's Small Favor; she'd been forbidden to talk about something by the Summer Queen.
In Orson Scott Card's Shadow of the Hegemon, Sister Carlotta finds out the particulars of Bean's condition from a scientist who first proposed the theory. The scientist has to be very clever about telling her, because he has been conditioned to have a panic attack whenever he speaks about or even thinks about his old work.
In Jonathan Strange & Mr Norrell, whenever Lady Pole or Stephen Black tries to tell anyone about the gentleman with the thistledown hair, they end up saying something completely unrelated and frequently nonsensical.
- Apparently it's actually stories that almost match up with ancient faerie activities, being The Fair Folk it sounds total nonsense.
The Aes Sedai in Robert Jordan's The Wheel of Time are unable to lie due to a magical promise on the Oath Rod; consequently, when asked a direct question about a secret, the best they can do is give a misleading but true answer. With the result that many people don't believe them at all, since they know about this oath. There's also reason to believe that the Black Ajah have a magical compulsion against betraying their fellow darkfriends, which is why they can't reveal names even under torture.
- The exact function of the Black Ajah oath is that is prevents them from divulging any of their secrets until the hour of their death. In the thirteenth book, one of them abuses this loophole by poisoning herself so that she can betray the Black Ajah to Egwene.
Germain from Eric Nylund's A Game Of Universe claims to have a Tongue-Tied spell placed on him, so that he can infiltrate a castle without anyone asking too many questions.
One of the Big Bads (there were three) of Callahan's Lady, written by Spider Robinson, can make anyone do whatever she asks of them, including failing to convey information. Fortunately thinking outside the box/in terms of puns, tends to work very well. "Please do not go down the stairs," is solved by leaping into the dumpster from an upstairs window.
The Harry Potter universe has multiple ways of invoing this:
- The Fidelius Charm might cause this. The charm makes it so that once a secret is entrusted to the Secret Keeper, the only way to discover the secret is for the Secret Keeper to tell you. One effect of this is that if you're told the secret by the Secret Keeper then you can't tell it to anyone else, but Canon doesn't establish how this is done. In might do it via Tongue-Tied (which is always how it happens in fanfic), it could cause a Contrived Coincidence to prevent a confession whenever you open your mouth to speak it, or or it could be something else entirely.
- There actually is a literal and Canon example of a tongue-tying charm in Harry Potter. When a Secret Keeper dies, everyone who knows the secret becomes a Secret Keeper. This includes Snape, though he probably wouldn't have told anyway. To prevent him from blabbing, Moody places a literal tongue twister curse on the house, preventing him from revealing its location.
Sheri S. Tepper's The True Game series has an unusual variant: a character is prevented from speaking a certain piece of information, but is perfectly capable of writing it down. However, this bit of Tongue-Tied is contagious: any person who reads the information will be unable to speak it aloud, even if they've never met the beings who laid the Tongue-Tied magic on it.
In James Thurber's The 13 Clocks, the wicked duke had a curse put on the Princess Saralinda so that she can only say "I wish him well" in the duke's presence.
Mages in the Heralds of Valdemar series can place this spell on others. Ethical mages will only do it with permission.
In the Warcraft novel War of the Ancients, Neltharion casts this spell on a Krasus coming from the future to prevent him from revealing his plans.
In The Belgariad by David Eddings, the protaganist Belgarion is spied upon by the Grolim Asharak (aka Chamdar) from his childhood days but a magical compulsion prevents him speaking about it until the spell is broken.
In a short story by Selma Lagerlöf, a young girl kidnapped by bandits has to solemnly swear she'll never tell what happened and where they're hiding to anyone. After escaping, she tells how to find them to her cat, while the family's in the room.
Part of Sophie's curse in Howl's Moving Castle includes the inability to explain or describe the curse to anyone else.
Non-informational variant: In Master of Five Magics, sorcerers become progressively more Tongue-Tied when they recite their spells, which must be repeated three times without error to be effective. By the third recitation, they're usually struggling desperately to get their lips and tongue to shape the right sounds, not slip up and incur the mystical backlash from a botched spell.
The title character of Spider's Song is born tongue-tied and mute. He's tongue is "accidentally" cut free by a friend who doesn't remember doing it afterward.
Labyrinths of Echo had this happened a few times, both in the main series and prequels. The "non-disclosure" enchantments and oaths are fairly common in the World of Rod. Some kill the subject trying to reveal the secret, others simply prevent talking. Even with the safest enchantments, the problem is that when they directly clash against magic used to get the prohibited answer (or even non-specific mind control effects used to force revealing the secret), results tend to be weird and very messy.
- It's not automatically foolproof, however. Juffin on a hunt for his former apprentice the first time ran into an explosive mishap, the second time he told the victim to say nothing, analyzed the magic, and concluded: "This enchantment is strong, but it was done by an airheaded dolt. Tell me the exact opposite of what's going on."

Live Action TV

In one episode of Angel Lorne returns from a mission to gather information saying, "I can't talk about it. No, literally, they did a spell." He then subverts it by giving it to Angel in writing instead.
In a Muppet version of The Frog Prince, a princess is cursed to speak in scrambled sentences so that she couldn't tell that the witch who cast the spell is masquerading as the king's sister. The frog prince is the only one able to understand her, perhaps because he was transformed by the same witch.
- Or that Robin had more than two brain cells to rub together. The Princess's father wasn't exactly Einstein, you know.
In Farscape, after Harvey (Scorpius's mental clone) has to reveal himself to John, he briefly edits his subconscious and makes him unable to talk about it.
In one episode of Jam, a lift in an office breaks down but the security guard, who has a speech impediment, physically can't get the words out in time to warn people. Several people step into the lift and fall to their deaths because he can't call out to them in time.

Music

Red Dwarf had the quote providing song as a fantasy sequence in one episode.

Radio

The song itself was first aired several years previously in BBC radio comedy Son of Cliche, set to music by Peter Brewis using words written by Brewis and Grant/Naylor.

Tabletop Games

D&D's Book of Vile Darkness includes a spell called "Forbidden Speech" which pretty much lets the caster specify one topic that the subject/victim will be unable to talk, write, or even telepathically communicate about.
- In a recent campaign, a friend's wizard put this spell on a particularly ego-centric and irritating character of mine, with the taboo being... Herself. Cue the laughter.
- In adventure I12 Egg of the Phoenix, High Cleric MacKurian is put under a Geas spell that prevents him from writing or saying the name of the Big Bad.
- Exalted has a a similar spell, but in this case, the victim of the spell is subjected to wracking pain and uncontrollable vomiting whenever they try to talk about the forbidden subject. In addition to being much more sadistic, this version is probably less useful, since anyone who's heard of the spell will know that something's up.
The ritual Plague of Hiccups in Unknown Armies afflicts the victim with a fit of hiccups whenever he speaks a particular phrase. The snag here is that the hiccups don't trigger until after the victim speaks the phrase so it can't completely prevent discussion of the subject, just make it rather inconvenient.
Exalted also has the Ebon Dragon charm known as "Our Little Secret", in which you can render someone unable to tell anyone about what they saw you doing by making them feel guilt and shame. This can quite specifically only be used when the act in question would horrify the average person in the local culture.

Video Games

The plot of Kingdom Hearts 2 begins when a mysterious thief steals photos from everyone in town. It would be almost mundane, if not for everyone's sudden inability to say the word photo afterward.
The Ancient Conspiracy of the Metal Gear Solid games inject their agents with nanomachines that cause them to say nonsensical "La-li-lu-le-lo" when attempting to discuss them. See The Last Days of Foxhound example below.
One of the effects of Doopliss stealing Mario's body in Chapter 4 of Paper Mario: The Thousand-Year Door is Mario being unable to use his name. When he attempts to tell it to Vivian when she asks for it, she is unable to understand what he is saying (even moreso than we usually do).
- It seemed like it was less of being able to understand him and more of being able to HEAR him - her response seems to indicate that, for example, Mario tried to say something but nothing came out, or it did come out but so quiet that she couldn't hear anything.

Web Comics

Gunnerkrigg Court: Coyote does this to Annie about the tooth he gave her: 'If you tell anyone in the forest about the tooth, even Ysengrin, this bind will snip off your hand'.
In The Last Days of Foxhound, Revolver Ocelot secretly brainwashes his teammates into being incapable of saying "The Patriots", the secret organization he works for. Instead, it comes out at "LA-LI-LU-LE-LO"

Psycho Mantis: That conniving backstabbing son of a bitch SANTA CLAUS!"

- Confirmed by the Metal Gear Solid Database. Further confirmed by MGS4; at one point Snake mentions the Patriots, to which a confused Meryl replies, "La-li-lu-le-lo?"
In Sluggy Freelance, Gwynn curses Torg to make donkey noises when he tries to tell people about the fact that she's using magic again. Unfortunately, her wording was a bit too broad. Not only does he start hee-hawing when he tries to say any important information (like "Zoe, help! Oasis has kidnapped me and taken me to a Poconos Resort to force me to marry her!"), he starts actually turning into a donkey!

Web Original

Miriam of Making the Cut is forced to not tell any of her friends that's she's been turned into a vampire, and the vampires are forcing her to be their spy.

Western Animation

One episode of The Amazing World of Gumball has incompetent guidance counselor Mr. Small accidentally doing this to Gumball and Darwin: when his attempts to break them from lying fail, he resorts to traumatizing them into silence with a puppet. Then he stumbles into the drawer of his own filing cabinet and gets locked inside. Gumball and Darwin try to help, but they're incapable of verbalizing what's going on to anyone.

Real Life

Non-disclosure agreements.
- Also known as "gag orders."
Strictly speaking, it is possible to be born literally tongue-tied, with the tip of the tongue attached to the bottom of the mouth. It can cause mild speech deformation, so some doctors "clip" it.