Contrast (linguistics)

In linguistics and semantics contrast is a relationship between two discourse segments. Contrast is often overtly marked by contrastive markers like but or however, such as in the following examples:

1. It's raining but I am taking an umbrella.
2. We will be giving a party for our new students. We won't, however, be serving drinks.

In (1) the first clause, It's raining implies that the speaker will get wet, while the second clause I am taking an umbrella implies that the speaker will not get wet. Both clauses (or discourse segments) refer to related situations, or themes, yet imply a contradiction. It is this relationship of comparing something similar, yet different, that is believed to be typical of contrastive relations. The same type of relationship is shown in (2), where the first sentence can be interpreted as implying that by giving a party for the new students, the hosts will serve drinks. This is of course a defeasible inference based on world knowledge, that is then contradicted in the following sentence.

The majority of the work on contrast and contrastive relations in semantics has concentrated on characterizing exactly what semantic relationships can give rise to contrast. Much early work in semantics also concentrated on identifying what distinguished clauses joined by and from clauses joined by but.

In discourse theory, and computational discourse, contrast is a major discourse relation, on par with relationship like explanation or narration, and work has concentrated on trying to identify contrast in naturally produced texts, especially in cases where the contrast is not explicitly marked.