I met the last speaker of Naati on an empty stretch of beach on Malekula, an island in the South Pacific nation of Vanuatu. I had been hiking for hours along narrow paths through the hot, dense forest, wading across the occasional waist-high stream with my pack of recording equipment hoisted overhead. As I dropped my pack on the sand, a figure descended from the nearby cliffs and crossed the beach toward me.

We exchanged greetings in the local creole, and the conversation quickly turned to the topic of my unlikely appearance on these shores. I told the man, Ariep, that I was in the country to study one of its many Indigenous languages. When he learned I was a linguist, he excitedly shared that he speaks Naati.

Plunging several sticks into the sand and using them as reference points, Ariep explained the relationship between Naati and the other languages of the area. With a mix of pride and sorrow, he revealed that he is the last fluent speaker of Naati. Although a few of his family members have some knowledge of the language and make an effort to use it together, he fears that with his death, Naati will soon disappear.

Naati’s predicament is not unique. Of the roughly 7,000 languages spoken on the planet today, 50 to 90 percent are considered vulnerable to extinction by the end of the century.

Language is the cultural glue that binds communities together.

The crisis has received increasing public attention over the past decade, punctuated by lines such as “one language dies every two weeks” and illustrated by poignant tales of the death of a last speaker. In this UNESCO International Year of Indigenous Languages, as alarm bells sound and preservation efforts are celebrated, we should pause to ask: Why does it matter?

Should Naati’s fate concern the world? Ariep does not need Naati to communicate. Like many speakers of endangered languages, he is fluent in an impressive number of languages, including several native to his island, as well as the national language.

If we are heading toward a future in which we all speak one of a few large languages, isn’t that a good thing? Couldn’t it be a way to facilitate communication and level the playing field across nations? Is the desire to “save” these small languages purely sentimental—a romantic notion fostered by scholars in ivory towers of isolated peoples untouched by the exhausting rush toward globalization?

I argue “no.” As a linguist who has worked with endangered language communities in Canada and the Asia-Pacific, I know that language loss is a critical and urgent problem—not only for the speakers who lose their languages, but for everyone. Languages are a vital source of culture and identity for individual communities, and for the global community, languages are an invaluable source of information about human cognition. A linguistically diverse world benefits us all.

Consider what has happened to people whose language has been forcibly taken from them, supplanted by one of the larger, ostensibly more useful languages. This scenario has played out countless times across centuries at the hands of colonial powers or as a tool of national governments to suppress minority groups. It occurs around the world today in classrooms where children are punished or humiliated for using languages and dialects that deviate from an accepted standard.

The response of these communities has not been to celebrate the subsequent generations who speak English, Spanish, Swahili, or whatever the language of power might be. Rather, they decry this cultural genocide and, where possible, fight back against the theft of their linguistic heritage.

In Canada during the 19th and 20th centuries, many Indigenous children were forced to attend residential schools like this one in Fort Resolution, Northwest Territories, where they were punished for speaking their native languages. Library & Archives Canada/Flickr

In Canada during the 19th and 20th centuries, the national government oppressed Indigenous people in part by removing children from their families and placing them in residential schools. In these spaces, children suffered a range of physical and mental abuses, including punishment for speaking their languages. These injustices severely disrupted the transmission of dozens of Indigenous languages, the majority of which are now endangered.

Today, despite a scarcity of resources to address numerous challenges after decades of persecution, Indigenous Canadian communities are making huge investments in reclaiming their languages. From the “language nest” in Tyendinaga Mohawk Territory in Ontario, where children are exposed only to Mohawk throughout the day, to the Nehiyawak language and culture camps in Saskatchewan, where families learn and share their Cree heritage, Indigenous language education across Canada is flourishing.

It would seem easier, cheaper, and infinitely more practical just to accept English (a language that is no less highly desirable internationally) and shift the resources elsewhere. The fact that people struggle to reclaim their languages despite the obstacles says something crucial about the value of language and the tragedy of loss.

Language is the cultural glue that binds communities together. Language loss is a loss of community heritage—from histories and ancestral lineages known only through oral storytelling, to knowledge of plants and practices codified through words unwritten and untranslated.

A man in Uganda eats live white ants (termites), a traditional practice associated with several words in the Lulamogi language. Eye Ubiquitous /Getty Images

Lulamogi speakers in Uganda, for example, worry that as people forget the dozens of terms that describe methods of trapping and eating white ants—such as okukunia, okutegerera, and okubuutira—they will forget this important cultural practice. Also at risk are the phrases and associated customs for welcoming the agricultural seasons and washing the bodies of the dead.

In the words of Lulamogi language advocate Nabeeta Erusaniah: “It is like when a wall of a hut collapses, the ceiling does not remain standing. What keeps the social practices and a ritual standing is the language. Kill the language, and the shelter collapses too.”

Language loss is also a loss of community identity, collective purpose, and self-determination. While harder to quantify, such losses have real, detrimental effects on health and quality of life. Conversely, the ability of community members to speak their Indigenous language together enhances well-being.

In British Columbia, youth suicide rates are more than six times lower in Indigenous communities where at least 50 percent of the population speaks the native language. In Aboriginal and Torres Strait Islander communities of Australia, young people who speak an Indigenous language have lower rates of binge drinking and illegal drug use compared to nonspeakers, as well as a decreased chance of becoming victims of violence.

The disappearance of a language may seem like an unfortunate loss only to the people involved. However, the impact for all of us is real and substantial.

This impact goes beyond the losses of particular bits of information, like Indigenous names for medicinal plants yet to be classified by scientists outside a community, or concepts and worldviews reflected in the words and structures of one language that do not have parallels in another. Understanding language is vital to understanding human cognition. Each language is a piece of the puzzle that we need in order to determine how language works in the mind. With each missing piece, we are further from seeing the full picture.

Analyzing language patterns has real implications for our lives.

Languages may appear to differ wildly from one another, but they are all variations on a theme. Like a field of flowers, the individual plants may vary in height and color, but they all have stems and petals.

Your language may have “tall trees” or “trees tall.” It may ask, “Where is the dog?” or “The dog is where?” It may thank you in one syllable or in many. Regardless, whether your language is spoken or signed, it draws on a limited set of forms and structures, and it uses them in consistent and predictable ways.

The remarkable similarities across languages suggest that there is some cognitive capacity that underlies all human language, directing how language develops and setting the boundaries for what is possible. The goal of contemporary linguistics is to describe and model this system—in essence, to figure out how language works.

For example, languages contrast greatly in their number of consonants, from the six in the Papuan language Rotokas to the 122 in the southern African language ǃXóõ. There are enough commonalities among sound systems, however, that if linguists know your language has 20 consonants, we can make a fairly good guess as to what many are likely to be, and we can be almost certain of others that would not occur. In terms of sentence structure, all languages use the three basic elements subject, object, and verb. Although these can be ordered in different ways, about 80 percent of known languages put the subject first, while only about 1 percent put the object first.

Analyzing these patterns is far from an esoteric academic exercise; it has real implications for our lives. The more we understand about how language functions, the better equipped we are to improve our therapies for communication disorders and our methods for language teaching.

This knowledge contributes to technological innovation as well. Research on sound patterns is used in creating speech synthesis software, while models of grammatical structure aid in developing linguistic components for artificial intelligence.

Understanding language in turn gives us a window into cognition. Observations about the strikingly similar ways that children acquire language, across languages and cultures, provide insight into how the brain develops. Psycholinguistic experiments involving language production, comprehension, and recall tasks reveal clues to how the mind organizes information.

Early models of grammar were based primarily on a few large, mostly European, languages that Western scholars knew or could easily access. Imagine the deficiencies if the research stopped there. It would be like basing an understanding of plants on a neighborhood vegetable garden or of animals on a trip to a petting zoo.

This UNESCO chart depicts hundreds of endangered and vulnerable languages by continent. Thousands more are predicted to disappear by the end of the century. NavinoEvans/Wikimedia Commons

Recent reports on gender bias in medical testing have revealed that therapies tested on men do not necessarily work for women. Studies of racial bias in the tech industry have shown that applications such as facial recognition, which were trained on images of white people, do not necessarily work for people of color. When it comes to language, what if our models are proven incorrect by a previously undocumented cluster of languages in the Amazon? A theory of human language must account for the language of all humans.

However, taking into account all languages, or even a representative sample, is a huge challenge. Thousands of languages are undocumented or only very poorly described, and no one—neither linguists nor speakers—understand how they work.

Documenting a language thoroughly is a major undertaking involving years of collaboration between the members of a speech community and linguists (who may or may not be speakers themselves). Given the rapid rate of language loss in the world today, many languages are in danger of disappearing before they have been documented, taking with them irreplaceable information about human cognition.

The very limited documentation we have of Naati reveals that the language has a sound called a “bilabial trill.” These trills were once considered impossible speech sounds, but now linguists know that they are common in the languages of Malekula.

As I watched Ariep turn back toward the cliffs that day on the beach, taking with him a wealth of linguistic and cultural knowledge, I wondered, Does Naati contain other features that could challenge our understanding of language?

What can the many undocumented languages teach us about language structure and cognition, about the richness of our cultures and traditions, about our very humanity? For the sake of the speakers of endangered languages, for the sake of us all, we must preserve the world’s languages as we search for answers and work to ensure linguistic diversity for generations to come.