Carmel O'Shannessy was a featured speaker at workshop on Variation and asymmetries in case-marking, held at the Australian National University, July 31. The workshop brought together international researchers working on morphology and syntax in languages with case-marking, to share ideas on factors contributing to variation in expression of case-marking, asymmetries in case-marking and methods for analyzing this variation. Carmel's paper provided a description of optional ergative case-marking in Light Warlpiri, in comparison with Warlpiri. The data were narratives from children and adults collected at three time periods - 2005, 2010 and newly collected data from 2015. the abstract for Carmel's talk is given below.

Optional ergative-case marking in Light Warlpiri and Warlpiri

Abstract: It is not uncommon to find that obligatory case-marking has become optional in a language, especially one that is endangered or obsolescing. But surprisingly, in Light Warlpiri the frequency of ergative case-marking on overt subjects of transitive verbs has increased from an average of 59% in adult and child texts recorded in 2005 to an average of 79% in children's texts recorded in 2010. This brings the amount of marking inline with that in Warlpiri texts told by the same cohort of multilingual speakers. In 2005 the function of ergative marking in Light Warlpiri included indicating postverbal and inanimate subjects of transitive verbs, and indicating heightened agentivity of an agent, including when there was contrastive focus. In Warlpiri the function was also to indicate postverbal subjects of transitive verbs, and clauses that were highly transitive. Since there is considerably more marking in the 2010 Light Warlpiri texts, the function is expected to have changed. This paper traces the function of ergative marking in Light Warlpiri and Warlpiri texts at the two time points.