Internal evidence for final vowel lowering in Hausa

Internal factors involving phonotactic asymmetries and irregular morphological alternations suggest that final */uu/ in Hausa historically lowered to /oo/ when the preceding syllable contained /aa/, e.g. *kwaacfoo 'frog' < *kwaacfuu. (Note: L tone is indicated by a grave accent, H tone is left unmarked. Long vowels are indicated by double letters.) The aim of this paper is to present evidence supporting this proposal and to suggest implications of the historical vowel change for one of Hausa's many plural formations, the ablaut plural. (For background studies on the history of vowels in Hausa and Chadic, see Barreteau [1987], Frajzyngier [1986], Newman [l979b], Parsons [1970], Schuh [1984], and Wolff [1983].)