Vowel Quality Alternation in Dinka Verb Derivation: The Agar Variety

In Dinka, a predominantly monosyllabic and highly fusional Western Nilotic language, vowel quality alternation in the root plays a major and systematic role in the morphology of verbs, together with alternations in vowel length, voice quality, and tone. Earlier work has shown that in the inflection of simple, i.e., underived, transitive verbs, the vowel quality alternation conforms to a vowel height gradation system with three vowel grades. The present article shows that this vowel gradation system is also operative in the morphology of derived verbs with a transitive root, but with certain modifications. These include a different distribution of the vowel grades and interaction with a shift in voice quality, to breathy voice.