Nez Perce Vowel Harmony and Proto-Sahaptian Vowels

Nez Perce vowel harmony involves two groups of co-occurring vowels: /i e u/ and /i a o/. Most words contain only one of the two groups of vowels. Certain morphemes are variable and may have vowels of either group, while others have only the second group. The latter type of morpheme, whether stem or affix, dictates the vowel harmony. Three analyses, one in terms of prosody, and two in terms of distinctive features, are given, in an attempt to derive the modern Sahaptian vocalic systems from that of Proto-Sahaptian.