Language isolate

One example is the Ket language spoken in central Siberia, which belongs to the wider Yeniseian language family; had it been discovered in recent times independently from its now extinct relatives, such as Yugh and Kott, it would have been classified as an isolate.

[5] Since linguists do not always agree on whether a genetic relationship has been demonstrated, it is often disputed whether a language is an isolate.

Hattic, Gutian, and Kassite are all considered unclassified languages, but their status is disputed by a minority of linguists.

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.

[14] "Vibrant" languages are those in full use by speakers of every generation, with consistent native acquisition by children.

"Moribund" languages have only a few remaining native speakers, with no new acquisition, highly restricted use, and near-universal multilingualism.

"Extinct" languages have no native speakers, but are sufficiently documented to be classified as isolates.

With few exceptions, all of Africa's languages have been gathered into four major phyla: Afroasiatic, Niger–Congo, Nilo-Saharan and Khoisan.

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.

[18] Current research considers that the "Papuasphere" centered in New Guinea includes as many as 37 isolates.