Editing Navajo language (section)

==Classification==
Navajo is an [[Athabaskan languages|Athabaskan language]]; Navajo and Apache languages make up the southernmost branch of the family. Most of the other Athabaskan languages are located in Alaska, northwestern Canada, and along the North American Pacific coast.

Most languages in the Athabaskan family have [[tone (linguistics)|tones]]. However, this feature evolved independently in all subgroups; [[Proto-Athabaskan]] had no tones.<ref>{{Harvnb|Hargus|Rice|2005|p=139}}</ref> In each case, tone evolved from [[glottalic consonant]]s at the ends of morphemes; however, the progression of these consonants into tones has not been consistent, with some related morphemes being pronounced with high tones in some Athabaskan languages and low tones in others. It has been posited that Navajo and [[Chipewyan language|Chipewyan]], which have no common ancestor more recent than Proto-Athabaskan and possess many pairs of corresponding but opposite tones, evolved from different dialects of Proto-Athabaskan that pronounced these glottalic consonants differently.<ref>{{Harvnb|Hargus|Rice|2005|p=138}}</ref> Proto-Athabaskan diverged fully into separate languages {{circa|500 BC}}.<ref>{{Harvnb|Johansen|Ritzker|2007|p=333}}</ref>

Navajo is most closely related to [[Western Apache language|Western Apache]], with which it shares a similar tonal scheme<ref>{{Harvnb|Hargus|Rice|2005|p=209}}</ref> and more than 92 percent of its vocabulary, and to [[Mescalero-Chiricahua language|Chiricahua-Mescalero Apache]].<ref>{{Harvnb|Levy|1998|p=25}}</ref><ref>{{Harvnb|Johansen|Ritzker|2007|p=334}}</ref> It is estimated that the [[Apache]]an linguistic groups separated and became established as distinct societies, of which the Navajo were one, somewhere between 1300 and 1525. Navajo is generally considered [[mutual intelligibility|mutually intelligible]] with all other Apachean languages.<ref>{{Harvnb|Koenig|2005|p=9}}</ref>