Dependent Case by Agree: Ergative in Shawi

Ergative and accusative behave as dependent cases insofar as their appearance on a nominal depends on the presence of another nominal in the same domain. Recent work on case theory has taken the phenomenon of case dependency to challenge the idea that case is assigned via the operation Agree. Focusing on the Shawi language (Kawapanan; Peru), we show not only that patterns of case dependency can be captured via Agree, but also that doing so opens up a new way of understanding the typology of global case splits. Ergative in Shawi appears when the subject is at least as high as the object on the person hierarchy—a global split pattern—and can be accompanied by explicit realization of the object’s features on the subject nominal (“object agreement on the subject”). We propose that ergative arises in Shawi when a probe on v Agrees with both the object and the subject, transferring object features to the subject; these features are spelled out as ergative case and as object agreement. In general, we show that dependent cases, both ergative and accusative, can be seen as a morphological outcome of syntactic Agree between a probe and a second goal, realizing features on that goal that were transferred from a previous goal in an earlier step of Agree.