Animacy and information structure in the system of ergative marking in Umpithamu

This paper describes a system of ergative marking in Umpithamu (Cape York Peninsula, Australia), in which the use of the ergative marker is determined by a combination of principles of animacy and information structure. Inanimate transitive subjects receive obligatory ergative marking, whereas animate transitive subjects only receive ergative marking when they are in focus, defined here as a principle of local prominence. Further evidence for this analysis is provided by showing that the principles governing optional ergative marking also govern other aspects of morphosyntactic organization, specifically the position of pronouns and the marking of objects. The system in Umpithamu is compared with other optional ergative systems in Australia, and it is shown that the principle of local prominence is unusual, with most other languages relying on more global, episode-level types of prominence. This also has a number of theoretical implications, including the need to recognize different construction types in applying rules for case marking in transitive clauses, and the challenge of mixed categories to the modular organization of grammatical models.