Adversative coordinative conjunctions necessarily involve a contrast between two elements related to the utterances they coordinate. Contrast is a heterogeneous concept. In this article, three types of contrast are identified: restrictive, corrective and additive. These types give rise to three different readings of the adversative coordinative conjunctions. In this work, a semantic function for each type of contrast is proposed, and the presuppositional character of restrictive contrast is defended. These hypotheses lead us towards the discourses in which the coordinative adversative conjuncts are inserted. The discourse has to contain alternatives such that when the type of contrast is not univocally lexicalized, the alternatives will guide the interpretation of the conjunction