Abstract In everyday conversation, participants sometimes misunderstand or fail to trust each other, and then negotiate in order to achieve mutual comprehension and/or agreement. The chances of misunderstandings/distrust will be even greater, and the negotiation process may be more complicated when there is a significant gap in the participants' linguistic competency, and they do not share communicative and socio-cultural norms for participating in a conversation. This study investigates misunderstandings, distrust, and negotiations in face-to-face interactions between native speakers of English and those of Japanese. Data were collected from approximately 18-hour long, audio-taped, dyadic conversations conducted in English. Discourse analytic approaches to these data produced twofold results. First, the results show what factors may trigger misunderstandings/distrust; such communication problems stem not only from Japanese speakers' incompetence in their second language(for example, mispronunciation of an English word and lexical errors)but also from English speakers' inadequate inferences and conflicts between their knowledge of various kinds and that of Japanese speakers(e.g., encyclopedic knowledge of a certain place, culture). Second, the results suggest that the negotiations are co-constructed by the participants as follows; a negotiation sequence typically starts with English speakers' requests for elaboration or clarification, inviting Japanese speakers' elaboration, clarification, or self-repair, and ends with a topic change. In cases of distrust, English speakers may deploy a joke, negative evaluation, sarcasm, or claim advantages for their own knowledge over the others' knowledge.