Language isolate

A **language isolate**, in the absolute sense, is a natural language with no demonstrable genealogical (or "genetic") relationship with other languages, one that has not been demonstrated to descend from an ancestor common with any other language. Language isolates are in effect language families consisting of a single language. Commonly cited examples include Ainu, Basque, Korean, Sumerian, Elamite, and Vedda, though in each case a minority of linguists claim to have demonstrated a relationship with other languages.

Some sources use the term "language isolate" to indicate a branch of a larger family with only one surviving member. For instance, Albanian, Armenian and Greek are commonly called Indo-European isolates. While part of the Indo-European family, they do not belong to any established branch (such as the Romance, Indo-Iranian, Celtic, Slavic or Germanic branches), but instead form independent branches. Similarly, within the Romance languages, Sardinian is a relative isolate. However, without a qualifier, *isolate* is understood to mean having no demonstrable genetic relationship to any other known language.

Some languages once seen as isolates may be reclassified as small families. This happened with Japanese (now included in the Japonic family along with Ryukyuan languages such as Okinawan). The Etruscan language of Italy has long been considered an isolate, but some have proposed that it is related to the so-called Tyrsenian languages, an extinct family of closely related ancient languages proposed by Helmut Rix in 1998, including the Rhaetian, formerly spoken in the central Alps, and the Lemnian language, formerly spoken on the Greek island of Lemnos.

Language isolates may be seen as a special case of unclassified languages that remain unclassified even after extensive efforts. If such efforts eventually do prove fruitful, a language previously considered an isolate may no longer be considered one, as happened with the Yanyuwa language of northern Australia, which has been placed in the Pama–Nyungan family. Since linguists do not always agree on whether a genetic relationship has been demonstrated, it is often disputed whether a language is an isolate or not.

## "Genetic" or "genealogical" relationships

The term "genetic relationship" is meant in the genealogical sense of historical linguistics, which groups most languages spoken in the world today into a relatively small number of families, according to reconstructed descent from common ancestral languages. A "genetic relationship" is a connection between languages, like similarities in vocabulary or grammar, that can be attributed to a common ancestral proto-language that diverged into multiple languages or branches. For example, English is related to other Indo-European languages and Mandarin Chinese is related to other Sino-Tibetan languages. By this criterion, each language isolate constitutes a family of its own, which explains the exceptional interest that these languages have received from linguists.

## Looking for relationships

It is possible that all natural languages spoken in the world today are related by direct or indirect descent from a single ancestral tongue. The established language families would then be only the upper branches of the genealogical tree of all languages, or, equally, lower progeny of a parent tongue. For this reason, language isolates have been the object of numerous studies seeking to uncover their genealogy. For instance, Basque has been compared with every living and extinct Eurasian language family known, from Sumerian to Kartvelian, without conclusive results.

In some situations, a language with no ancestor can arise. This frequently happens with sign languages—most famously in the case of Nicaraguan Sign Language, where deaf children with no language were placed together and developed a new language. Similarly, if deaf parents were to raise a group of hearing children who have no contact with others until adulthood, they might develop an oral language among themselves and keep using it later, teaching it to their children, and so on. Eventually, it could develop into the full-fledged language of a population. With unsigned languages, this is not very likely to occur at any one time but, over the tens of thousands of years of human prehistory, the likelihood of this occurring at least a few times increases. There are also creole languages and constructed languages such as Esperanto, which do not descend directly from a single ancestor but have become the language of a population; however, they do take elements from existing languages.

## Extinct isolates

Caution is required when speaking of extinct languages as isolates. Despite their great age, Sumerian and Elamite can be safely classified as isolates, as the languages are well enough known that, if modern relatives existed, they would be recognizably related.

However, many extinct languages are very poorly attested, and the fact that they cannot be linked to other languages may be a reflection of our poor knowledge of them. Hattic, Gutian, and Kassite are also believed to be isolates by mainstream majority, but their status is disputed by a minority of linguists. Many extinct languages of the Americas such as Cayuse and Majena may likewise have been isolates. A language thought to be an isolate may turn out to be relatable to other languages once enough material is recovered, but material is unlikely to be recovered if a language was not documented in writing.

## Sign language isolates

Further information: Deaf-community sign language, Village sign language
A number of sign languages have arisen independently, without any ancestral language, and thus are true language isolates. The most famous of these is the Nicaraguan Sign Language, a well documented case of what has happened in schools for the deaf in many countries. In Tanzania, for example, there are seven schools for the deaf, each with its own sign language with no known connection to any other language. Sign languages have also developed outside schools, in communities with high incidences of deafness, such as Kata Kolok in Bali, the Adamorobe Sign Language in Ghana, the Urubu Sign Language in Brazil, several Mayan sign languages, and half a dozen sign languages of the hill tribes in Thailand including the Ban Khor Sign Language.

Studies are also being conducted on Al-Sayyid Bedouin Sign Language (ABSL) in an isolated village in Israel. The language was developed in isolation for over 75 years by both deaf and hearing people within the village.

These and more are all presumed isolates or small local families, because many deaf communities are made up of people whose hearing parents do not use sign language, and have manifestly, as shown by the language itself, not borrowed their sign language from other deaf communities during the recorded history of these languages.

## List of language isolates by continent

Below is a list of known language isolates, arranged by continent, along with notes on possible relations to other languages or language families.

The Status column indicates the long-term viability of the language, according to the definitions of the UNESCO *Atlas of the World's Languages in Danger*. "Vibrant" languages are those in full use by speakers of every generation, with consistent native acquisition by children. "Vulnerable" languages have a similarly wide base of native speakers, but a restricted use and the long-term risk of language shift. "Endangered" languages are either acquired irregularly or only spoken by older generations. "Moribund" languages have only a few remaining native speakers, with no new acquisition, highly restricted use, and near-universal bilingualism. "Extinct" languages have no native speakers, but are sufficiently documented to be classified as isolates.

### Africa

Further information: Languages of Africa#Unclassified languages
With few exceptions, all of Africa's languages have been gathered into four major phyla: Afroasiatic, Niger–Congo, Nilo-Saharan and Khoisan. However, the genetic unity of some language families, like Nilo-Saharan and Khoisan, is questionable, and so there may be many more language families and isolates than currently accepted. Data for several African languages, like Kwadi and Kwisi, are not sufficient for classification. In addition, Jalaa, Shabo, Laal, Kujargé, and a few other languages within Nilo-Saharan and Afroasiatic-speaking areas may turn out to be isolates upon further investigation. Defaka and Ega are highly divergent languages located within Niger-Congo-speaking areas, and may also possibly be language isolates.

### Oceania

The languages of New Guinea are poorly studied, and candidates for isolate status are likely to change when more becomes known about them.