Language isolates: the languages with no known relatives

Most languages sit on a family tree. Spanish and Hindi are distant cousins in Indo-European, and Swahili belongs to the Bantu branch of Niger-Congo. A language isolate has no tree. The historical linguist Lyle Campbell defined one as "a language which has no relatives, that is, that has no demonstrable genetic relationship with any other language," and added that isolates "are in effect language families with only one member."

An isolate may well have had relatives that died out without being written down. What matters is that none can be shown today. Linguists group languages by comparing vocabulary and grammar and finding regular sound correspondences between them. When that comparison finds nothing, the language stands alone.

How many language isolates are there?

There is no single agreed number, and the gap between counts is wide.

Glottolog puts 7,674 spoken first languages into 246 families and 183 isolates, so roughly two in five of its lineages are families of one. Its count includes extinct languages that are known only from writing, which is why Sumerian appears on it. It also keeps a separate list of 128 languages that are unclassifiable because too little of them was ever recorded.

The counts also differ because the compilers made different calls on borderline cases, several of which are covered below.

Where isolates cluster

Isolates are not spread evenly. In Matthias Urban's 2021 study in Royal Society Open Science, South America had 66 isolates and 50 families, the only region where isolates outnumbered families. Papunesia, the region around New Guinea, had 54 isolates, North America 32, Africa 16, Eurasia 12 and Australia 9. By that tally, 98 of 189 isolates, just over half, are in the Americas.

Within South America, Urban found that isolates "cluster in the western margins of Amazonia." He also observed, calling it an impression rather than a finding, that the places where isolates cluster tend to be places with many languages of every kind, and gave the Upper Amazon and California as examples. Campbell's regional counts point the same way: 55 of his 136 isolates were in South America.

Basque, Europe's last one

Basque is the isolate most people have heard of. Urban calls it "the only language isolate of Europe that is still spoken." Britannica describes it as the only remnant of the languages spoken in southwestern Europe before the region was Romanized in the 2nd and 1st centuries BCE. It is spoken today in an area of about 10,000 square kilometers (3,900 square miles) straddling the border of Spain and France.

The Basque government's 2021 sociolinguistic survey counted 680,629 Basque speakers aged 16 and over in the Basque Autonomous Community, 36.2% of that age group. Across the whole Basque-speaking region, including Navarre (14.1%) and the French Basque Country (20.1%), the survey found that 30.2% of 2,683,858 residents aged 16 and over speak Basque. That works out to roughly 810,000 people.

Other living isolates

Burushaski is spoken mainly in the Hunza, Nagar and Yasin valleys of northern Pakistan. Britannica estimates about 90,000 speakers. A 2023 report in Himal Southasian put the number at around 100,000 in Gilgit-Baltistan, plus about 350 people in a Burusho community in Kashmir. Campbell names Burushaski, with Basque and Ainu, as one of the three best-known isolates.

Kusunda, in Nepal, is close to the end. Glottolog classifies it as nearly extinct. According to the Nepali Times in June 2025, Kamala Sen Kusunda has been the only native fluent speaker alive since Gyani Maiya Sen Kusunda died in 2020. Only 253 people identified themselves as Kusunda in Nepal's 2021 census. Classes run with support from Nepal's Language Commission had 20 students, not all of them Kusunda.

Zuni, in New Mexico, is on Campbell's list of North American isolates. Glottolog rates it as "shifting" on its endangerment scale.

The borderline cases

Much of the disagreement between counts comes down to a few languages that are either isolates or tiny families, depending on what you count as a separate language.

Ainu, from northern Japan, is one of Campbell's three best-known isolates. Glottolog treats it as a small family of three: Hokkaido, Kuril and Sakhalin Ainu. It lists Hokkaido Ainu as nearly extinct. Researchers are building speech recognition and speech synthesis for it; a 2026 paper by Kawahara and Matsuura at the ComputEL-9 workshop describes that work "for the preservation and revitalization of the Ainu language."

Korean works the same way. Campbell's 2010 survey lists Korean among Asia's isolates. Glottolog puts it in the Koreanic family with Jejueo, spoken on Jeju Island, which makes it a family of two. Haida, on the Pacific coast of Canada and Alaska, and Nivkh, in the Russian Far East, get the same treatment: isolates for Campbell, two-language families for Glottolog.

Isolate or just unknown?

An isolate is different from a language we simply know too little about. Campbell draws the line this way: an unclassified language is one "for which there is not enough data" to know whether it has relatives, while an isolate has been documented and compared, and the comparison "does not reveal linguistic kinship." Glottolog uses the same rule for its unclassifiable list.

Urban adds a caution that the boundary between the two "is not clear-cut, and the assessment is to some extent subjective." A language recorded from a single word list in the 1800s can drift from one category to the other as scholars reread the same material.

Isolates that only survive in writing

Some isolates are known only from texts. Sumerian, the language of ancient Mesopotamia's earliest cities, is described by Glottolog as "an extinct ancient language isolate." Elamite, from what is now southwestern Iran, has no family in Glottolog either. Both were written for centuries and then stopped being spoken, so they will never gain or lose relatives through new fieldwork, only through new readings of what already survives.

Being an isolate today also does not mean a language was always alone. The American Philosophical Society, writing about Tunica, a language of the lower Mississippi valley, notes that "as is the case with many language isolates, it is likely that related languages once existed." Many isolates may be the last surviving branch of a family whose other members disappeared without being recorded. For more on how many languages that leaves, see how many languages are there in the world, and for the people who do this comparison work, what a linguist actually does.