Ordering arguments about: Word order and discourse motivations in the development and use of the ergative marker in two Australian mixed languages

Light Warlpiri and Gurindji Kriol are mixed languages which are spoken in northern Australia. They systematically mix the lexicon and morpho-syntax of a traditional Australian language (Warlpiri and Gurindji) and an Australian contact variety (Kriol), bringing systems from the source languages into functional competition. With respect to argument disambiguation, both Warlpiri and Gurindji use a case marking system, whereas Kriol relies on word order. These two systems of argument marking came into contact and competition in the formation of the mixed languages. The result has been the emergence of word order as the dominant system of argument disambiguation in the mixed language, the optionality of the ergative marker, and a shift in the function of the ergative marker to accord discourse prominence to the agentivity of a nominal.