If aliens invaded, how would we talk to them?

In the sci-fi film Arrival, alien spaceships suddenly appear above twelve locations on Earth. The aliens—seven-limbed creatures called heptapods—are willing to let a few humans come aboard for quick chats, but there’s no universal translator gizmo to help the two species parley. Instead, each country calls upon its top linguists, including Louise Banks, played by Amy Adams.

Banks is whisked away to the nearest spaceship in Montana, tasked with untangling the heptapods’ languages and figuring out why they have come to Earth. To find out how linguists might react when faced with an extraterrestrial language, the filmmakers consulted Jessica Coon, a professor of linguistics at McGill University in Montreal.

“These aren’t your typical Star Trek aliens that have two arms and two legs and a vocal system just like ours, but happen to be a different color or have strange bumps on their heads,” Coon says. “They’re really not human looking at all and the sounds that they make are completely nonhuman sounds, and that’s probably more likely what we would expect to find.”

We asked Coon about what the film gets right about field linguistics, why alien languages will be difficult to decipher, and how linguists might go about doing so.

Aliens will play by a different set of rules

If aliens ever do touch down on Earth, their language is likely to offer challenges not found in any human language. “What linguists have discovered about human languages is that even though they can sound very different from one another and their grammars do show a lot of variation…languages tend to fall into certain patterns,” Coon says. So given certain pieces of information about a human language, linguists can often make reliable predictions about its other properties.

Take word order. In languages where verbs come before objects, it’s also common for prepositions like “on” to precede nouns. So in English, we say, “ate the apple,” and, “on the table.” In other languages, such as Japanese, both patterns are reversed. “Most of the world’s languages fall into one of those patterns or the other,” Coon says. “The variation isn’t completely unconstrained.”

Alien languages are unlikely to follow the same rules that human languages share. “Humans seem to be hardwired for this capacity to learn language,” Coon says. “Because it is part of our genetics and part of being human, it’s very unlikely that other creatures…would have the same kinds of constraints or show the same kinds of similarities that human languages do.”

And experiences that can be represented in every human language may not show up in an alien one. Every human language will have some way of representing intent, Coon says. “Kids are going to want to be able to say, ‘I didn’t mean to break that cup.’” But, as Banks explains to her colleagues in Arrival, if an alien species acts instinctively their language may have no concept of self-will, or no way to distinguish between doing things on purpose as opposed to by accident.

Linguists won’t even be able to assume that an alien language will have nouns, verbs, questions and other elements that are basic building blocks of our speech. “We would just have to hope…that we would still be able to recognize patterns and match it up with we’re seeing,” Coon says.

Even our own biology could limit us from understanding an alien language. Assuming our visitors even have mouths, we still might not be able to pick apart the speech they utter. In Ted Chiang’s “Story of Your Life,” the short story that inspired Arrival, Banks’s character points out that human ears and brains are built to understand speech made using a human vocal tract. But when it comes to aliens, she says, “it’s possible our ears simply can’t recognize the distinctions they consider meaningful.”

While they are able to make progress with the aliens’ unique written language, Banks and her colleagues are hampered by an inability to reproduce the heptapods’ noises. “With the spoken language it’s just a nonstarter because she can’t produce these strange sounds that sound like whale calls and purring cats,” Coon says.

So how would we talk to aliens?

For her first fieldwork assignment, Coon spent a summer in Mexico learning the Mayan language Ch’ol. “Going to the site of a recently arrived UFO isn’t really anything like driving into the jungle in Chiapas,” she admits. Still, Coon says, Louise Banks’s attempts to decipher the heptapods’ languages in Arrival offer a pretty accurate representation of how we would try to translate alien speech.

If future linguists find themselves facing down intelligent aliens, they will have to introduce themselves, communicate what they want to do, and practice speaking or writing with the aliens. Like Banks, linguists will start small, understanding very basic terms before working up to more complicated questions.

“The film doesn’t really go into the nitty gritty details of how exactly she deciphered the language…but I think they did a very nice job piecing together the montage scene of Amy Adams and Jeremy Renner working together and acting out different scenes, and getting translations for basic things you can point to, and you see her poring over the logogram looking for patterns,” Coon says. “I think that’s exactly what linguists would be doing if they do call us to translate for aliens.”

When deciphering human languages, most field linguists bring along a few simple tools, such as an audio recorder (and perhaps a video camera), some pencils and paper, and whatever information they already have about their target language or related languages. “That’s always a good starting place,” Coon says. For any new language, she says, “Really it’s about interacting with speakers and asking lots of questions, and building up hypotheses about how the grammar works, and testing them by asking speakers more questions and refining our understanding of detailed parts of the grammar.”

What can we learn from afar?

So actually being able to interact with aliens will be key. But what if we can’t get close enough to attempt discourse with our alien guests? Linguists might still be able to make some progress with recordings, Coon speculates.

In the film, Banks’s first chance to hear the newly arrived aliens arises when a military officer plays her a brief audio file and asks what she can figure out from it. “That is obviously an impossible task, you need some kind of matchup between the sound and what’s being said,” Coon says. But Banks might have had more luck with videos and some knowledge of what context shaped the scene. If she had access to a large number of longer recordings, she could look for noises that reliably correspond to particular actions. “With enough of that kind of information…you could sort of whittle away at the grammar of a language,” Coon says.

Ancient human languages have been deciphered without help from living speakers. “If you have enough information and enough of the context and the history, I think there’s hope that even without a lot of interaction you could be able to make at least significant progress in understanding the grammar of a language—again depending on how likely we are to be able to understand alien life at all,” Coon says.

Does this mean that we could pick up an alien language from their broadcasts, or that they could learn ours? “I wouldn’t be surprised at all if creatures who could make giant spaceships that just show up on Earth could easily figure out our languages from the many broadcasts we put into outer space, and that we might be able to do the same thing with sufficient resources and sufficient information,” Coon says.