The origins of tense-based case marking in Pitta-Pitta and Wangkajutjuru

Several Australian languages show tense marking on non-verbal items, including the Karnic languages Pitta-Pitta and Wangkajutjuru (formerly spoken in Western Queensland). In these languages the forms of core case markers and the ergative/accusative split vary according to the tense and mood of the clause. Here I describe tense marking in the languages and the differences between sources and dialects, and discuss the etymologies of the case markers. I discuss sources for the future-marking construction and argue that these tense-marking patterns arose from the reanalysis of a construction which marked reduced transitivity. While several other constructions have been proposed in the literature as the source for Pitta-Pitta's case marking, I argue here that they do not adequately account for all the facts.