Africa is a continent where grammaticalized case systems are a rare phenomenon. Of the roughly 2,000 languages there are only a few with grammaticalized case, probably less than one-tenth of all African languages. Of the two basic case systems, (nominative/)accusative and ergative(/absolutive) distinguished worldwide, the latter hardly occurs in Africa, and the former accounts for less than one-third of all African case languages. The majority of African case languages, that is, roughly two-thirds, belong to the so-called marked-nominative type. Elsewhere in the world, marked-nominative systems are virtually non-existent.
African case languages show an areal and genetical distribution: Afroasiatic and Nilo-Saharan are primarily the phyla with case languages. Eastern Africa is a region with a high concentration of case languages in general and of marked-nominative languages in particular. In the border region of Uganda, Kenya, Ethiopia, and Sudan, marked-nominative languages are nearly the only type of case-marking languages to be found. Neighboring marked-nominative languages may belong to different phyla, namely Afroasiatic or Nilo-Saharan. In this chapter it is argued that marked-nominative systems are at least to some extent an areal phenomenon.
Introduction
Marked-nominative case systems stand out against other types of case systems, their defining property being that in such systems the nominative case is functionally marked vis-à-vis the accusative case (see section 8.2.1 for more details).
In the relevant literature, the phenomenon of marked-nominative languages has been recognized mostly from the perspective of each regional philology: Cushitists, Berberologists, and Niloticists all have looked at the phenomenon within their own language subgroup.