The sad truth is, you won't be able to speak a language upon hearing it for the first time.note You may not remember, but you couldn't even speak English upon hearing it for the first time. Language is learned and not instinctual. If you've ever been to a non-English-speaking country or if you're not a native English speaker, you already know this.
In fiction, however, characters can often carry conversations in languages they've had no exposure to before. A common variant of this trope is a newborn, often an anthropomorphic animal, being able to speak in complete sentences. Another common variant is a newly created monster, clone, or other human-like creature talking. In the case of monsters, this is often downplayed, with the creature being able to speak, but not fluently. In some works, this is treated as perfectly normal, while in others, only one character will have this unique ability. Inexplicably Speaks Fluent Alien is a subtrope. Contrast Bilingual Dialogue, for when two characters understand each other but are not fluent in each other's language, Language Barrier, for when a character cannot communicate with another, and Never Learned to Talk, for when a character does not speak any language. Compare Bilingual Backfire, for when two characters are talking about a present third party in another language to prevent them from understanding only to realize that the third party does understand the language, Cunning Linguist, for when a character is skilled at picking up languages, and Translator Microbes. May overlap with Suddenly Bilingual if the ability springs out of nowhere. Often the case for a character who Speaks Fluent Animal. If somebody's fluency in every language is explained they may be an Omniglot instead. Can result in Genetic Memory. May overlap with No Translation Necessary.
Examples
- Ultimate Fantastic Four:
- Downplayed. Namor demonstrates this trope after spending nine thousand years of being sealed inside a sarcophagus prison. Being from an ancient civilization of Atlantis that predates the modern English language, he initially has no idea what his new captors are saying when they find him. However, thanks to his psionic powers he proves to be a frighteningly fast learner and is able to learn English within an hour to understand modern American English and casually deliver threats and demands.
- Happens again when the Four meets the Silver Surfer who is able to understand English perfectly the instant he arrives to Earth for the first time. He justifies this by stating can decipher electromagnetic signals in the air to learn alien tongues in seconds.
- Infinity Train: Seeker of Crocus: Kaito is somehow able to read Aztec glyphs just by looking at it. This is probably due to his covenant with Agares, as one of Agares' ability is to let his conjurer read and understand different languages.
- The Mountain and the Wolf: The Wolf demonstrates the ability to speak not just the language of Westeros (even with a Brief Accent Imitation) but also of the Dothraki, Valyrian, the giants' language, and animals and babies. In actual fact it's a power the Chaos Gods have bestowed on him, but that isn't figured out for a while.
- Not Another Alicorn
: Rainbow Dash's Past-Life Memories makes her fluent in Unicornian, a pre-Equestrian language. The first time she demonstrates it, she doesn't even realize, having picked up and flipped through one of Twilight's books and made some comments on the subject matter, only for Twilight to point out that the book is written in a language that only Celestia and Luna can understand anymore.
- Three Sheets to the Wind: In a moment that leaves Roma speechless, the drunken boy who can barely stand or see well understands perfectly everything the mute Neo tells him. Rome decides that it's better not to question what Jaune can do and asks Neo to stop encouraging him to talk to her.
- In Atlantis: The Lost Empire the Atlanteans are able to fluently communicate with the explorers from the surface in English and French. This is handwaved as their own language being a precursor to all other languages.
- In Charlotte's Web, when Wilbur is transported to Zuckerman's farm, a talking goose is shocked by his quietness and asks him if can talk. He shakes his head. She then asks him if he ever tried, and he shakes his head again. She then encourages him to try, and he says his name... and then breaks into a song full of words he's never even heard.
Wilbur: [singing] Isn't it great that I articulate? Isn't it grand that you can understand?
- Pocahontas: English explorer John Smith meets the alluring Pocahontas of the Powhatan tribe. Smith doesn't know her language, nor she his. That is, until Pocahontas takes a breath of magic wind. Suddenly, her English is better than his.
- Aquaman (2018): When Atlanna first arrives in Amnesty Bay, Maine, she already knows English words even before the montage of her spending time with Tom — despite the relative lack of contact between Atlantis and the surface world.
- Inglourious Basterds: A random French dairy farmer living in the middle of nowhere in 1941 inexplicably speaks pretty good English, as does a random low-ranked German soldier who's occupying France.
- Downplayed in Phenomenon. After a UFO encounter, George gains a form of superintelligence where he can learn complicated tasks and subjects quickly, to the point where he's able to fluently speak Portuguese after reading an English-to-Portuguese dictionary for twenty minutes.
- Superman IV: The Quest for Peace: While Nuclear Man isn't exactly fluent in English, it's a wonder he can speak it at all considering that he's less than a day old.
- The Shivers (M. D. Spenser) novella, "One Foot in the Grave", is set in France, where the American protagonist moves to the French countryside because of her father's job. She meets a French boy her age (approximately 10) and they can somehow converse perfectly, an unexplained plot hole a review in Goodreads rants about
.
- Stardust Classics: When Kat and Jessie travel to the past, they can understand and speak any language around them without issue. (While not fully applicable in their first trip to 1851 London, they're fluent in both Chinese and Italian in 13th century China.) However, they don't really know how to speak the languages after they return home and everything sounds like English to their ears.
- 'Allo 'Allo!: Frenchmen, Germans, and Italians can talk to each other. This is never explained.
- Babylon 5: Played with in "Lines of Communication"; at what is supposedly First Contact between the Minbari and Drakh, the Drakh unexpectedly demonstrate fluency in the Minbari language. Soon enough, one of the Minbari delegation reveals himself as The Mole who's been in secret contact with the Drakh all along.
- Carnivàle: During the fireball show, Samson secretly passes an old Crusader fob up to the stage during Lodz's psychometry act. When Lodz touches it, he's struck by visions of a holy war and begins chanting "In hoc signo vinces!" Ben, an uneducated farmboy, surprises Samson by translating even though he doesn't even recognize the language is Latin:
Ben Hawkins: By this sign we conquer... by this sign we conquer...
- One episode of How I Met Your Mother reveals Ted can speak ASL. It never comes up again after the gag where Ted tips off a woman that Barney is trying to sleep with her by pretending Ted is his deaf brother (and once in another episode when he says "nice to meet you" to a deaf man).
- Zig-zagged in Friends. "The One Where Ross Can't Flirt" has Phoebe speaking with Joey's Italian grandmother, with Phoebe seeming as surprised about this as Joey. But in an earlier episode, Rachel's former lover Paulo calls her "bellissima" and she doesn't understand.
Joey: Wow, Phoebs, you speak Italian?
Phoebe: Apparently. - Llan-ar-goll-en: In "Dirgelwch y Llyfr Coll", Prys and Barti speak to each other in Swahili. It seems incredibly unlikely that Prys would be fluent in that language, and Barti only speaks in unintelligible grunts with individual words thrown in. The other characters barely react to this.
- Rakenzarn Tales: When the protagonist finds the titular book, he's able to read it despite the language being completely unknown to him.
- The Fairly OddParents!: Foop in the episode "Anti Poof". He's not even a day old, and is already talking like an adult.
- She-Ra and the Princesses of Power: Adora is able to instinctively read the language of the First Ones. Other characters can learn to decipher it, but Adora can just glance at a text and know what it says. While she's eventually revealed to be the last remaining member of the First Ones race, the last time she potentially had contact with any of them was as an infant (and even that's just a guess), so it's not as if they could have taught her.
- The Simpsons: Despite his general lack of intelligence, several episodes have Homer suddenly demonstrating fluency in a foreign language with little to no explanation. In one case even speaking Penguin.
- Superman: The Animated Series: In the episode "Identity Crisis", this is first played straight, with Superman's clone Bizarro speaking perfect English. As Bizarro becomes less like Superman and more monster-like, however, this is downplayed, and his English deteriorates.
- What If?: Kahhori (pronounced "Ka-HOR-tee") is a native Mohawk woman who initially only speaks the Mohawk language. But by the end of her first appearance, she is also somehow able to speak Spanish to speak with Queen Isabella of Spain. In her second appearance, she also somehow learned to speak English.

