This chapter is a second voyage of exploration and discovery. On the first trip my purpose was to locate critical points at which language becomes relevant to social research by examining situations in which such critical points are dramatically highlighted [1968].1 It was an attempt to identify language-related problems in cross-cultural research, a situation in which the participants generally recognise that more than one language is involved and that something needs to be done about language. The present paper considers some of these same critical points in situations where they are more obscure i.e. where people proceed on the assumption that they are communicating in "the same language".