The Plains Apache language (or Kiowa Apache language) was a Southern Athabaskan language formerly spoken by the Plains Apache, organized as the Apache Tribe of Oklahoma, living primarily around Anadarko in southwest Oklahoma. The language is extinct as of 2008, when Alfred Chalepah, Jr., the last native speaker, died. Plains Apache is the most divergent member of the Southern Athabaskan languages, a family which also includes Navajo, Chiricahua Apache, Mescalero Apache, Lipan Apache, Western Apache, and Jicarilla Apache. As a member of the broader Athabaskan family, it has an extremely complex system of verbal morphology, often enabling entire sentences to be constructed with only a verb. Phonology This article follows the orthography of Bittle (1963); where this differs from the IPA, IPA is given between slashes. Consonants Plains Apache has a large consonant inventory resembling that of its close relatives Navajo and Western Apache. The phoneme is only found in prefixes and does not occur before . is in free variation with preceding and also does not occur before . The fricated alveolar and postalveolar series are tend to be realized as slightly retroflex preceding and , though these variants are in free variation with the unretroflexed realizations. The plain alveolar and velar series are slightly fronted preceding and , and slightly backed and rounded preceding . Vowels Plains Apache distinguishes four vowel qualities, much like the other Southern Athabaskan languages. Additionally, all vowels may be either short or long and nasal or oral. Length is indicated in the orthography by writing the vowel twice (e.g. , 'water'); nasalization is indicated with an ogonek (e.g. , 'earth'). When long, the realization of tends to be closer to , and when short, closer to . An analogous alternation is true of , although this variation is more free, and is lexicalized by some speakers in certain words. Syllable Structure The Plains Apache syllable is maximally CCV:C, e.g. 'pants', though initial clusters are rare and must co-occur with a long vowel, making most syllables (C)V(:)(C), e.g. 'cactus' and 'dust'. All consonants may appear in the syllable onset, although and a null onset are not permitted word-initially; only and may appear in the syllable coda, whether word-final or not. Tone Plains Apache has a register tone system with two levels, low and high. Low is written with a grave accent (e.g. , 'bank'), and high is written with an acute accent (e.g. ,