How to invent a realistic language for fictional speakers

The distant moon Pandora from James Cameron’s Avatar films is a feast of sci-fi world-building. Dragonlike creatures prowl the skies. Supersmart whalelike beasts write poetry under the sea. And a splendid variety of jungle plants glows multicolor in the dark.

Cameronʼs famously stunning visual effects can make these ecosystems appear vivid enough to touch. But perhaps the most realistic feature of life on Pandora requires no high-tech cameras nor special effects to render: The language spoken by its native Na’vi people, though invented for the Avatar franchise, is very real. Some Avatar fans have even learned to speak it.

The mastermind behind this made-up tongue is Paul Frommer. As a linguist at the University of Southern California in Los Angeles, he’s fascinated by the structure of languages. So when Frommer heard that Cameron was looking for someone to build a language for the first Avatar film, he jumped at the chance.

“What would it be like to create a language that people could actually speak, that would be entirely new?” Frommer recalls thinking. “That was all tremendously exciting.”

Na’vi is far from the only constructed language, or conlang, in fiction. Language scholar J.R.R. Tolkien began work on the Elvish tongues that appear in The Lord of the Rings long before writing the books, and modern linguists have come up with conlangs for all kinds of characters in movies, TV and other media.

Creating a conlang involves much more than stringing together some make-believe words. Languages are complex machines with many interlocking parts, and linguists must wield their expertise in these systems to create functional languages that suit their fictional speakers. That careful engineering not only adds depth and realism to many fantastical realms. It may also offer insight into the nature of language itself.

Making sound decisions

Since the most basic building blocks of any spoken language are sounds, the first thing many language creators — or conlangers — do is nail down their sound system.

There’s an “incredible variety of speech sounds in the world’s languages,” Frommer says, and different languages use different subsets of those sounds. Deciding which ones to include in a conlang is like choosing spices to flavor a dish, he says. “You say, ‘OK, I want this to have kind of a Middle Eastern flavor, so I’m going to use these spices. I want it to have sort of an East Asian flavor, so I’m going to use those spices.’ ”

For Avatar, Cameron had already brainstormed the names for some characters and Pandoran wildlife. “It kind of had a bit of a Polynesian feel,” Frommer says, so he gave Na’vi a similar phonetic flavor. Polynesian languages, for instance, often have voiceless consonants such as “t” and “k,” made without activating the vocal folds, but not the voiced versions of those sounds: “d” and “g.” Na’vi does the same thing.

Linguist Marc Okrand took a different tack in creating an alien language for Star Trek in the 1980s. In Star Trek films and TV shows, Klingons hail from a planet some 100 light-years from Earth. A language that evolved so far away, Okrand figured, should sound as unfamiliar to most earthlings as possible — especially to Star Trek’s English-speaking audience.

To that end, Okrand loaded up Klingon with a combination of speech sounds not found together in any real-world language, including some that don’t exist in English. One, written as [H], is the throaty sound at the end of the German word “Bach” or in the middle of the Hebrew toast “l’chayim.” Another, written as [tlh], sounds sort of like the “dl” sound in “waddle.” (This is actually the sound that starts the word “Klingon” in Klingon, which has no “k” sound.)

Linguistic anthropologist Christine Schreyer faced almost the exact opposite challenge as Okrand when she crafted a conlang for the 2018 film Alpha. Since the movie is set in Europe around 20,000 years ago, Schreyer needed to create an authentic-sounding human language. The problem was, no one knows how people spoke back then.

“I looked at what are called protolanguages,” says Schreyer, of the University of British Columbia’s Okanagan Campus in Canada. Protolanguages are the estimated ancestors of modern languages. Scholars can sketch one out by comparing known languages. The common patterns among related tongues hint at what their common ancestor — the protolanguage — was like.

Researchers had devised three protolanguages representing what people in Europe and Asia might have spoken around the time Alpha was set. So Schreyer used a blend of the sounds from each in her conlang, Beama. Not all of those sounds exist in English. Beama also had “more popping sounds” called ejectives, Schreyer says, which are heard in some African and Indigenous American languages. She and a colleague described the work in 2021 in Philosophical Transactions of the Royal Society B.

Word-building

Armed with an inventory of sounds, a conlanger needs to come up with rules for how those sounds interact. “Every language has rules about what can start its words, what can end its words,” Schreyer says. English, for instance, ends many words with “ng” but doesn’t start words that way. Some African and Asian languages — and Na’vi — do.

Languages also have distinct ways of linking sounds into syllables. Some languages, such as English and Georgian, have many dense clusters of consonants. Others, like Hawaiian, favor more vowel-heavy syllables. Picking a conlang’s syllable structure helps define its character. Beama mimics the vowel-heavy syllables in one of the protolanguages that inspired it.

Once a conlanger knows how their phonetic puzzle pieces fit together, they are ready to start building words. There’s not necessarily a rhyme or reason to this part. Sometimes conlangers fashion words to reflect their meaning, the way the English word “kaboom” sounds a bit like an explosion. Frommer used this principle, known as iconicity, when he gave the Na’vi word for “smooth” — “faoi” — a soft slide of vowels and encrusted the word for “rough” — “ekxtxu” — with a bunch of consonants. But in conlangs, as in real-world languages, “typically there is no relation between sound and meaning,” Frommer says. “It’s arbitrary.”

Languages do have specific rules for how their words may shape-shift to fit different situations. In English, adding “s” can turn a singular noun plural, and adding “ed” can change a verb from present to past tense. Those are two pretty simple suffixes. But world languages use a broad variety of linguistic accessories to dress their words for different grammatical circumstances, offering conlangers a wealth of inspiration.

Take nouns. They can be more than just singular or plural. “Nouns in Arabic distinguish singular from dual — exactly two of something — and plural,” notes David Peterson, a conlanger based in Garden Grove, Calif. In creating the High Valyrian language for HBO’s Game of Thrones, he gave nouns four different forms that depend on quantity.

Likewise, verbs can change based on more than just tense; they can also change depending on their aspect, which marks whether an action is ongoing or complete. David Peterson and his wife, linguist and conlanger Jessie Peterson, found a fun way to do this in their Firish language for the fire people in the Pixar film Elemental. The basic form of a Firish verb is ongoing action, but adding the suffix “ksh” marks it as complete. That suffix is based on a Firish verb that means to douse a flame — which is how the Petersons imagined that fire beings would describe something as being over.

Piecing together sentences

When it comes to arranging words into sentences, “there are certain top-level grammatical decisions you make,” David Peterson says. “Then you get progressively more complex.”

One top-level decision is noun and verb order. English usually has subject-verb-object order. A person (subject) creates (verb) a language (object). But it doesn’t have to be that way. To make Klingon as unusual as possible, Okrand gave it one of the least common word orders among world languages: object-verb-subject.

“Create a language. Create it bad, and then create the second one better.”

David Peterson
Conlanger based in Garden Grove, Calif.

As soon as you start working with a specific noun and verb order, “certain other structures are going to suggest themselves,” Jessie Peterson says. One such structure involves words called adpositions that describe the relationships between things: “to,” “in” and so on.

If a language has verbs come before objects, as English does, its adpositions tend to come before its nouns. Something might be “in boxes.” But in languages where objects come before verbs, such as Japanese, adpositions follow their nouns. “Instead of saying ‘in boxes,’ you would say ‘boxes in,’ ” Jessie Peterson says. Following these types of rules can make a conlang more realistic. In the case of High Valyrian, adpositions come after nouns to match its subject-object-verb order.

Deciding on word order is just the beginning of building out a language’s grammar. Plotting a conlang’s architecture for linking or nesting multiple ideas in a single sentence can get “really mind-twisty,” Jessie Peterson says.

At first, a conlanger may come up with only enough grammar rules to translate the necessary lines for a book, show or film. But no conlang is ever truly finished, the same way no natural language is ever done evolving. Frommer, for example, still debuts new aspects of Na’vi on his blog — including some words suggested by fans who speak the language.

Fictional language, real speakers

Days before the first Avatar movie premiered in 2009, Frommer received a shocking email. The long message was written by a stranger — entirely in Na’vi.

“My reaction was … ‘What? What is this all about?’ ” Frommer recalls. The emailer had somehow gotten ahold of a glossary of Na’vi words, along with interviews in which Frommer had described Na’vi grammar. “That gave me the idea that, yeah, this may very well catch on,” Frommer says. Indeed, a hub of Na’vi learners quickly assembled online, some of whom now speak the language more fluently than Frommer does.

Back in 2011, Schreyer got curious why so many people were studying a language designed for fictional speakers. She surveyed Na’vi learners online and got responses from nearly 300 people ages 10 to 81 from 38 countries. Some were big fans of Avatar and wanted to feel more connected to the film; others were just fascinated by languages. Schreyer shared the findings in 2015 in Transformative Works and Cultures.

“People were learning Na’vi so quickly,” Schreyer says. “I wondered how endangered language communities could replicate that.” Endangered languages are at risk of disappearing as their speakers die out or switch to speaking something else. Schreyer has worked with members of the Taku River Tlingit First Nation in Canada to revitalize their endangered ancestral language. After seeing how audio files, social media and other tools helped people learn Na’vi, Schreyer and colleagues brought some of those ideas to a website that helps people learn Tlingit words.

Na’vi is not the only conlang to draw real-world speakers. The nonprofit Klingon Language Institute has helped Star Trek fans study Klingon for decades. As of 2024, more than 400,000 English speakers had started Duolingo’s Klingon course.

Joseph Windsor, an expert in theoretical linguistics, estimates there are some 100 advanced Klingon speakers in the world today. He doesn’t count himself among them, though he does know enough to identify as a Klingon speaker on the Canadian census. About a decade ago, Windsor decided to use Klingon to test the limits of language learning. He looked at a feature of language called stress, which is the emphasis placed on different syllables to help distinguish a word’s meaning. It’s what sets the noun “record” apart from the verb “record.”

“Stress in Klingon, from a human language perspective, [is] completely unnatural,” says Windsor, of the University of Calgary in Canada. The rules for which syllables to stress are “really weird,” he says, and don’t follow the patterns seen in real-world languages. But when Windsor analyzed an 18-minute clip of seven advanced Klingon speakers talking, he found something surprising.

The speakers stressed Klingon syllables with 84 percent accuracy. To Windsor, this suggests that it doesn’t matter how convoluted a stress system is. If there are regular rules to memorize, the human brain can pick it up pretty well. Windsor and a colleague shared the findings in 2016 at a meeting of the Canadian Linguistic Association.

What makes a language

Recently, scientists have used conlangs to probe what our brains recognize as a language.

“What would it be like to create a language that people could actually speak, that would be entirely new? That was all tremendously exciting.”

Paul Frommer
Linguist at the University of Southern California in Los Angeles

The brain is known to process real-world languages using areas in the frontal and temporal regions of the left hemisphere. “They are highly connected [to] each other, all these regions that process language,” says MIT cognitive neuroscientist Saima Malik-Moraleda. This neural circuitry cares only about language. It doesn’t process other language-like means of expressing ideas, such as math or computer code.

Malik-Moraleda wondered how the brain handles conlangs. Does it treat a them the same way it does real-world languages, which have evolved among groups of people over many generations? Or does it treat conlangs like other invented types of communication, such as code?

To find out, Malik-Moraleda’s team recruited 10 Klingon speakers, eight Na’vi speakers, three people who knew High Valyrian and three people who spoke Dothraki. (David Peterson also invented Dothraki for Game of Thrones.) In brain scans, people’s language centers lit up when they listened to recordings of the conlang they knew, but those brain regions were not as active when participants did nonlanguage mental exercises. Malik-Moraleda’s team reported these findings in March 2025 in Proceedings of the National Academy of Sciences.

The findings offer clues to solving the mystery: “What makes a language a language?” Malik-Moraleda says. “Some of the things that differentiate constructed languages from natural language don’t seem to be relevant.” It doesn’t seem to matter, for instance, if a language was recently made up by a single person.

Instead, what may set languages apart in the brain is their ability to convey almost any meaning, Malik-Moraleda says. Languages, natural or constructed, “allow you to talk about inner and outer world experiences, what you’re thinking about but also what you’re experiencing in the world — in a way that maths and programming languages might not.”

Recreational conlanging

Conlangs designed for blockbusters, books and TV shows make up a small fraction of the world’s invented languages. People have been dreaming up conlangs for centuries to use for journaling, art, international communication and more.

“There are thousands of language creators all over the world,” David Peterson says. Some hobbyists have designed languages expressed through gestures, musical notes or even knots. “There are tons of conlangers who do really kind of wacky things,” he adds, pointing to the Rikchik language concocted by conlanger Denis Moskowitz as one example.

Moskowitz’s language is used by a race of imaginary creatures with 49 tentacles. “They basically move [seven of their] tentacles in different shapes to create glyphlike images,” David Peterson says. “It’s not possible for a human to use it in the conventional sense, because we lack the appropriate number of tentacles.” But there is a written form of the tentacular vernacular that people can use.

Conlanging is a pretty big sandbox, where people play around with language in all kinds of ways. You don’t need to be a linguist to join in, either.

Jessie Peterson took her first crack at making a conlang when she was 10 years old. Growing up in rural Missouri, she says, “I was fascinated by other languages but never had access to them.” So she made up a secret language to speak with her friends on the playground.

The key to becoming a good conlanger, the Petersons add, is studying many languages, especially unrelated ones. “Even if it’s not learned to any sort of fluency,” Jessie Peterson says, just sampling how different languages convey meaning “can really open your mind” to the possibilities.

“Then there’s just practice,” David Peterson says. “Create a language. Create it bad, and then create the second one better.”