Impersonal constructions in Umpithamu and the Lamalamic languages

In the four Pama-Nyungan languages Umpithamu, Morrobolam, Mbarrumbathama and Rimanggudinhma there is a core set of impersonals centred around experiencer object constructions. They describe involuntary physical processes, and are formally characterized by lack of nominative pronominal cross-reference, and optional absence of ergative agent nominals. In addition, systematic lack of nominative cross-reference is found in constructions with inanimate agents in all four languages, and in experienced action constructions in Umpithamu, in both cases with ergatively-marked nominals. It is argued that nominative cross-reference is the basic criterion for subject status, with ergative marking merely indicating agent status. Given the lack of any specific valency-changing morphology, impersonals with ergatively-marked nominals are functional equivalents of a voice mechanism, with agents demoted from subject status. This process has developed furthest in Umpithamu where the experienced action construction is systematically available as an alternative construal for a subset of transitive clauses. Keywords: impersonal; experiencer object; inanimate agent; passive; Umpithamu; Lamalamic