Ergativity, Agreement, and the Sumerian Verbal Complex
The Sumerian verbal complex displays a head-marking pattern that is split-ergative based on aspect. In the imperfective, subject marking follows the verbal stem and object marking preceding the verbal stem. In the perfective aspect, though, ergative marking precedes the verbal stem, and absolutive marking follows the verbal stem.
I argue on the basis of this split that Sumerian shows an ergative agreement pattern that identifies absolutive case with abstract nominative case (Woolford 1999), in which a probe in T⁰ establishes an Agree relation with the absolutive nominal. This account explains the alternation in the interpretation of the pre-stem and post-stem morphological slots, as well as predicts the simplified verbal template found in non-finite verbs.