The paper studies the language of sadness in English on a corpus of conventional expressions and aims at investigating the choice of prepositions combined with a number of sadness terms (e.g. sad about his failure, unhappy at his misfortunate, depressed by the news, sorry for being late). The paper finds that the prepositional phrases name the causes triggering sadness and there are correlations between the prepositions about, at, by, for and over and the types of causes combined together, which can be explained the metaphorical meanings of the prepositions.