In this volume leading academics in Interactional Linguistics and Conversation Analysis consider the notion of units for the study of language and interaction. Amongst the issues being explored are the role and relevance of traditionally accepted linguistic units for the analysis of naturally occurring talk, and the identification of new units of conduct in interaction. While some chapters make suggestions on how existing linguistic units can be adapted to suit the study of conversation, others present radically new perspectives on how language in interaction should be described, conceptualised and researched. The chapters present empirical investigations into different languages (Danish, English, Japanese, Mandarin, Swedish) in a variety of settings (private and institutional), considering both linguistic and embodied resources for talk. In addressing the fundamental question of units, the volume pushes at the boundaries of current debates and contributes original new insight into the nature of language in interaction.