This study documents the role of hand gestures in achieving mutual understanding in second-language learning situations. The study tracks the way gesture is coordinated with talk in tutorials between two Korean students and their American teachers. The study adopts an interactional approach to the study of participants' talk and gestural practices, while drawing on McNeill's taxonomy of gestures. It is aligned with studies that emphasise achievement--as opposed to failure or miscommunication--in second-language learning situations. In this study, three main functions of gesture are identified: (i) unpacking meaning, (ii) displaying alignment through gesture replication and (iii) displaying alignment through gesture co-production.