Syntactic ergativity as case discrimination

A variety of languages with ergative case systems show a ban on A' movement of ergative subjects. Such bans are the most common type of syntactic ergativity. This paper advances an analysis of ergative extraction restrictions as case discrimination—the requirement that the probe driving movement Agree only with a goal bearing a certain case. This analysis puts together the idea that A' movement is driven by heads which bear [EPP] and Agree in an operator-feature with Bobaljik's (2008) proposal that Agree may be possible only for DPs with certain types of case. A ban on ergative A' extraction arises when the A' probe can agree only with unmarked DPs, not with DPs in dependent case. This account explains why some languages have syntactic ergativity only for certain types of A' movement, and correctly predicts syntactic ergativity in languages where ergative cannot be treated as an inherent case.