Introducing an interpreter into a discourse event affects the very nature of the interchange because in addition to the interlocutors’ intersubjective approach to each other, the interpreter necessarily bases her interpretation on assumptions she makes about each of the interlocutors’ shared and non-shared knowledge. Recently, many American Sign Language (ASL)-English interpreters have espoused what have been termed “expansions”, claimed to be grammatically required in ASL. But ASL has no such “explicitness” requirement; instead the interpreter must attend to the intersubjective domain of discourse interaction in order to attempt to more accurately represent what is in the minds of the interlocutors. This paper explores triadic intersubjectivity in interpreted discourse and the role that “contextualization” plays in managing others’ shared and non-shared knowledge.