A language isolate is a natural language with no demonstrable genetic relationship with other living languages - ie, one that has not been proved to descend from a common ancestor to any other language. Commonly cited examples include Basque, Ainu, Burushaski, and Japanese, although in each case a minority of linguists claims to have demonstrated a relationship with other language (see Dene-Caucasian and Altaic.)

Some languages became isolates in historical times, after all their known relatives became extinct. The Pirahã language of Brazil is one such example, the last surviving member of the Mura family. Others, like Basque, have been isolates for as long as their existence has been documented.

Language isolates may be seen as a special case of unclassified languages, being languages which remain unclassified even after extensive efforts. If eventually such efforts do prove fruitful, a language previously considered an isolate may no longer be considered one; and since linguists do not always agree on whether a genetic relationship has been demonstrated, it is often disputed whether a language constitutes a true isolate or not.

Contents

1 Genetic relationship 2 Looking for relationship 3 Isolate, not Isolated 4 List of language isolates

Genetic relationship

The term "genetic relationship" is meant in the sense of historical linguistics, which claims that almost all languages spoken in the world today can be grouped by derivation from common ancestral languages into a relatively small number of families. Thus, for example, English is related to other Indo-European languages, and Mandarin to many other Sino-Tibetan languages. By this criterion, each language isolate constitutes a family on its own — which explains the exceptional interest that those languages have received from linguists.

Looking for relationship

It is possible (though not certain) that all languages spoken in the world today are genetically related, by descent from a single ancestral tongue; the established language families would then be only the upper branches of the genealogical tree of all languages. For this reason, isolate languages have been the object of numerous studies seeking to uncover their genealogy. Thus, for instance, Basque has been compared with every living and extinct language family known, from Sumerian to the South Caucasian — without conclusive results.

There are some situations in which a language with no ancestor might arise. For example, if deaf parents were to raise a group of hearing children who have no contact with others until adulthood, they might develop a verbal 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. Such a situation is not very likely to occur at any one time, but looking at tens of thousands of years of human history plus pre-history, the likelihood of this occurring at least a few times increases.

Isolate, not Isolated

One should not confuse the concept of a language isolate with a language whose speakers are isolated in some sense, e.g. because they have little contact with other cultures (like the language of Easter Island), or because they live far away from the regions where related languages are spoken (like the Malagasy language of Madagascar, whose closest relatives are spoken in Southeast Asia). These two languages are definitely not isolates.

List of language isolates

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

Language	Comments
Ainu	Endangered language, spoken in northern Japan.
Basque	No known living relatives, found in the Basque region of France and Spain. Aquitanian is commonly regarded as a direct ancestor of Basque. Some linguists have claimed similarities with various languages of the Caucasus, especially because of its ergative case system, but the resemblances seem superficial. Other linguists have proposed a relation to Iberic .
Birale (Ongota)	Often considered Afroasiatic
Burushaski	Little information available.
Elamite	Extinct language of Elamite Empire; some conjecture a relationship to the Dravidian languages
Etruscan	Language of the ancient Etruscans in northwestern Italy, not well understood at present
Hadza	Often listed as an outlier among the Khoisan languages
Iberic	There are lexical coincidences with Basque, but it is hard to know if they are more than a result of vicinity.
Jalaa
Japanese	Possibly related to Korean language, though not yet proven. Connections to the Altaic languages have also been proposed. See Altaic hypothesis for these theories.
Kalto	(also called Nahali) a near-extinct language of western India.
Ket	No known relatives. Some linguists have attempted to show a relationship with Burushaski.
Korean	Possibly related to Japanese language, though not yet proven. Connections to the Altaic languages have also been proposed. See Altaic hypothesis for these theories.
Kwadi	Often listed as an outlier among the Khoisan languages
Laal	Unclassified; sometimes considered Niger-Congo
Mekejir (Shabo)	Often considered Nilo-Saharan
Meroitic	Extinct language of ancient kingdom of Meroe (Kush)
Nivkh	or Gilyak. A Palaeosiberian language spoken in the lower Amur River basin and on the Sakhalin Islands; Ainu is also spoken on Sakhalin.
Oropom	Possibly nonexistent.
Pirahã	Related to languages that have recently become extinct. Only known language with no number terminology; only known language with no grammatical recursion; several other unique features.
Sandawe	Often listed as an outlier among the Khoisan languages
Sumerian	Long-extinct language of ancient Sumeria.
Taiap
Tarascan	Latest research suggests the possibility that it may be related to a family of languages from Ecuador
Ticuna
Yuchi	Connections to Siouan languages have been proposed
Yukaghir	Connections to Uralic Languages have been proposed
Zuni	Connections to Penutian languages have been proposed