Ergative, antipassive and other verb derivational morphemes in Gaahmg

Abstract Gaahmg has ergative traces in a predominately nominative-accusative system. Clauses with object focus demonstrate ergative case marking on postverbal noun and pronoun agents, and an ergative morpheme is also bound to verbs. Other evidence for ergativity is that the ergative morpheme is morphologically and syntactically distinct from the passive morpheme. Ergative morphemes and constructions in Gaahmg are similar to those of other Nilo-Saharan languages, including Luwo, Päri, and Shilluk. The Gaahmg antipassive also resembles that of other Nilo-Saharan languages. Yet, unlike other languages with ergativity and antipassives, Gaahmg readily combines the antipassive with ergative, passive, and causative morphemes in the same verb form. The Gaahmg antipassive occurs in nominative-accusative structures, as well as in object-focus clauses with ergative-absolutive structures. Further, the antipassive co-occurs with the passive, as if both the nominative-accusative and ergative-absolutive structures are simultaneously present in the same clause, and the language is currently shifting from one structure to the other.