Contrast, adversative and corrective can all be represented by er in Classical Chinese, but they are lexicalized respectively by er, danshi and ershi in Modern Chinese. The two lexicalization systems suggest that the opposition relations have commonalities as well as differences. In the framework of relevance theory and ‘three domains’, this study argues that the three opposition relations are in different cognitive domains, at different representational levels, and trigger different inferences, which accounts for their diverse lexicalizations in Modern Chinese. The opposition relations also have cognitive or metaphorical connections with each other, which justifies their unified actualization in Classical Chinese. The pragmatics-cognitive framework could also account for interlinguistic data.