A study investigated the relatively greater frequency of negation in conversation than in written language. It discovered that rejections and explicit denials of previously asserted propositions, two categories of negation postulated to be speech-specific, accounted for only about 16 percent of all negatives. Use of negatives as supports, in direct questions and imperatives, and in repetitions accounted for 37 percent of the negatives. Work in progress suggests that factors such as the degree of interaction and the expression of modality and mental attitudes, which often co-occur with negation, may explain further the use of negation. (Author/MSE)