The default assumption in human communication is mutual intelligibility between interlocutors. Nevertheless, misunderstandings also occur, and languages have resources for managing these in communicative interaction. When speakers do not share a native language, misunderstandings are generally expected to arise more frequently than between native speakers of the same language. However, it is not clear that communication breakdown is more common among second language users; the anticipation of communicative difficulty may in itself offset much of the trouble, and speakers resort to proactive strategies. This paper investigates misunderstanding and its prevention among participants in university degree programs where English was used as a lingua franca. The findings suggest that speakers engage in various clarification and repair strategies in an apparent attempt to ensure the achievement of mutual intelligibility and thereby the achievement of important communicative goals.