The paper deals with dialogical cases of the adversative coordinator mais / but / ale in French, English and Polish, following a corpus selected from modern works and their translations in the three languages. Whenever an example or its part (or an equivalent connective) happened to be missing from the translation, it was completed and then submitted for acceptance of the native speakers. According to the analysis and classification of data sources, there are two major discourse functions of dialogical mais / but / ale involved: 1) mainly illocutionary one, from which lecz - the Polish variant of ale - is completely excluded, and 2) combining the illocutionary and the adversative ones.