Vowel harmony in Yeyi

Yeyi (Bantu, R41) is an endangered language spoken in northwestern Botswana and northeastern Namibia. Yeyi exhibits two peculiar processes of regressive vowel harmony. The first changes a high front vowel /i/ to a back vowel /u/ when followed by a syllable containing a back vowel /u/, as in ʃi-púndi > [ʃùpúndì] ‘brat’, or /o/, as in ʃi-bowuma > [ʃu-bowuma] ‘kind of snake’, or the glide /w/, as in ʃi-hweta > [ʃuhweta] ‘conversation’. This paper analyzes these two vowel harmony processes in Yeyi, using data from a wide variety of published sources on different Yeyi regiolects. I will show that the use of vowel harmony differs between regional varieties of Yeyi, with certain varieties using vowel harmony in more phonological contexts than others. The diachronic functioning of vowel harmony is also discussed, comparing vowel harmony involving affixes to vowel harmony involving only lexical roots. Finally, a comparative perspective is taken, showing that regressive vowel harmony as used in Yeyi is rarely seen in Bantu languages of Southern Africa, but occurs sporadically in Khoe languages, suggesting that regressive vowel harmony in Botswana may be an areal phenomenon.