Apachean Languages

Apachean peoples speak one or more of seven Southern Athabascan languages, which have relatively similar grammatical structures and sound systems. Southern Athabascan (or Apachean) is a sub-family of the larger Athabascan family, which is a branch of the Nadene language family.

Navajo is notable for being the indigenous language of the United States with the largest number of native speakers. However, all Apachean languages are endangered, including Navajo. Lipan is reported extinct.
The Southern Athabascan branch was defined by Harry Hoijer primarily according to its merger of stem-initial consonants of the Proto-Athabascan series *k̯ and *c into *c (in addition to the widespread merger of *č and *čʷ into *č also found in many Northern Athabascan languages).
Hoijer (1938) divided the Apachean sub-family into an Eastern branch consisting of Jicarilla, Lipan, and Plains Apache and a Western branch consisting of Navajo, Western Apache (San Carlos), Chiricahua, and Mescalero based on the merger of Proto-Apachean *t and *k to k in the Eastern branch. When the Western languages have noun or verb stems that start with t, the related forms in the Eastern languages will start with a k.
He later revised his proposal in 1971 when he found that Plains Apache did not participate in the *k̯ var scriptParams = {"google_search_engine_id":"7903437290074846:8434550147"};