one of the largest North American Indian language (North American Indian languages) families, consisting of about 38 languages. Speakers of Athabaskan languages often use the same term for a language and its associated ethnic group (similar to the use of ‘English' for both a language and a people), typically naming these with some form of ‘person' or ‘human,' as with Navajo (Navajo language) diné. The Athabaskan family is a branch of the Athabaskan-Eyak subgroup of the Na-Dené language phylum (Na-Dené languages), which was named for the words for ‘person' in Tlingit and Athabaskan.

The languages in this family are spoken in three discontinuous geographic regions: the Pacific Coast, the southwestern United States, and northwestern Canada and the Alaskan interior. The languages of the Pacific Coast subgroup were spoken in northern California and southern Oregon by peoples including the Hupa, Mattole, Kato, Tututni, Galice, and Tolowa. Of these, only two languages, Hupa and Tolowa, are still spoken. The southwestern United States is home to the Apachean subgroup, which includes Navajo (Navajo language) and the languages spoken by the Apache peoples. The Apachean languages are spoken mainly in Arizona and New Mexico. The languages spoken in the interior of Alaska and northwestern Canada include those of the Carrier, Dene Sų{lbelt}iné (formerly Chipewyan), Dogrib, and Slave peoples. Most Athabaskan languages are in danger of becoming extinct. The languages with the greatest number of speakers are currently Navajo, Western Apache, Slave, Dogrib, and Dene Sų{lbelt}iné.

The Proto-Athabaskan Urheimat, or original homeland, is thought to have been a northern area with a watershed that drained into the Pacific Ocean, such as eastern Alaska or western Yukon. Three lines of evidence support this assumption. First, the kinds of words that can be reconstructed for Proto-Athabaskan (e.g., ‘mountain,' ‘snowshoe,' ‘travel by boat,' ‘caribou,' ‘loon,' ‘Chinook salmon') suggest familiarity with a northern landscape. Second, the other languages to which Athabaskan is related, Eyak and Tlingit, are also northern languages; they are spoken around the mouth of the Copper River in Alaska and the Alaska panhandle, respectively. Finally, some northern Athabaskan languages that are located adjacent to one another are linguistically very different; the deep differentiation of neighbouring languages suggests a long occupation of a territory.

A variety of loanwords, almost all of them nouns, have entered Athabaskan languages. Some have been adopted from neighbouring indigenous languages. The Witsuwit'en (spoken in British Columbia) words k^w'əsdəde ‘chair' and həda ‘moose' were borrowed from the Carrier kw'əts'əzda and the Sekani xəda, respectively. Gitksan, a Tsimshianic language spoken to the west, contributed x^wts'a:n or pts'a:n (‘totem pole'), which became ts'an in Witsuwit'en. The Witsuwit'en ləmes ‘mass' is from the French la messe; məsin ‘copper' is from the English machine. All extant Athabaskan languages use some English loanwords. French terms are mostly limited to the northern subgroup and were perhaps transmitted through Chinook Jargon or from another Athabaskan language (Carrier, in the case of Witsuwit'en). Other Indo-European sources have included Russian (for the northern languages) and Spanish (for the Apachean languages).

Athabaskan languages typically contain large inventories of consonants (consonant) (often 30 or more) and smaller inventories of vowels (vowel) (usually 5–7). Somewhat fewer than half of the languages have developed tonal contrasts from original syllable final glottalization; e.g., Proto-Athabaskan *te{lbelt}š{lbelt} ‘mat' \\> Tsek'ene tèl, where 【*】 indicates an unattested form, {lbelt} represents glottalization, and 【è】 is a low-tone vowel. Nouns are classified by their number, shape, and animacy; for certain types of verbs these characteristics are reflected in the choice of verb stem. For example, Witsuwit'en verb stems include stəy ‘it (animate) lies'; stan ‘it (rigid) is (in position)'; sə{lbelt}coz ‘it (clothlike, flexible) is'; səqay ‘it (shallow container) is'; sə{lbelt}dzəγ ‘it (liquid) is'; sət{lbelt}εγ ‘it (mushy) is'; sə'ay ‘it (general 3-dimensional object, abstract, nonmaterial) is'; səle ‘it (ropelike),' or ‘they (nonhuman) are'; and sədzec ‘they (granular) are.'

The formation of verb words is complex in Athabaskan languages. A single verb may contain many prefixes. Moreover, groups of verb prefixes with the same meaning may not necessarily be adjacent to each other in a verb word. For example, the Witsuwit'en verb wec'ontəzisyin' ‘I'm not going to pick berries' contains three prefix sequences: we-s-' negative (wec'ontəzisyin'), u-yin ‘pick berries' (wec'ontəzisyin'), and t-i- future (wec'ontəzisyin'), among other components. General syntactic characteristics of Athabaskan languages include subject-object-verb word order. For example, in the Tsek'ene sentence Sųs Alec dzidniiyòòt ‘The black bear scared Alec,' the noun sųs ‘black bear' is the subject, Alec is the object, and dzidniiyòòt ‘he/she/it scared him/her/it' is the verb. Wh- questions are often formed with in situ wh- question words—i.e., with the wh- word in the position expected of a corresponding noun or adverbial. For example, the Tsek'ene question Tlįį ma nàghìì'àdla? ‘Whom did the dog bite?” (tlįį ‘dog' + ma ‘whom' + nàghìì'àdla ‘he/she/it bit-wh') is related to the sentence Tlįį Alec nàghìì'àdl ‘The dog bit Alec.' Note that ma ‘whom' in the question occurs in the same position relative to subject and verb as does Alec in the corresponding sentence.