 He has worked extensively on the development of creole languages, especially Gullah and Jamaican Creole, on the morphosyntax of Bantu languages, especially Kituba, Lingala, and Kiyansi (the last of which he speaks natively), and on African American Vernacular English.He has also published several articles and chapters about language evolution.Mufwene received his Ph.D. in linguistics from the University of Chicago in 1979.