John Mansfield researches how the social uses of language are manifest in diverse language types, especially the Aboriginal languages of northern Australia. Language use reflects the social role of speakers, the stances they take in verbal interaction, and the unfolding of language change over time. Different language types offer speakers very different repertoires for expressing linguistic identity. John specialises in the Murrinhpatha and Marri Tjevin languages, both spoken at Wadeye in the Northern Territory. John’s main current research aims for Murrinhpatha are to analyse intergenerational change, document the social functions of different ways of speaking, and understand how the highly complex morphology of the language is evolving in a situation of rapid social change. For Marri Tjevin, John’s main focus is the description of phonological and morphological structure in this under-documented, highly endangered language. John has further research interests in the Anindhilyakwa language of Groote Eylandt, and the Reira Tangsa language of Arunachal Pradesh, India.