This chapter discusses the knowledge that we gain about emotions through data on language. Language provides us with a framework in which to understand emotions, and emotions are also indirectly present in our linguistic behaviour even though we do not discuss them directly. This chapter deals with what causes emotions and how people react to them, and how words and expressions for emotions feature in linguistic change. Linguistic change tends to be driven by general mechanisms such as metonymy, but linguistic expressions may also play a role. Most of the data represents written language because many examples come from historical data, which shows how language change factors in how we use words and expressions for emotions. Words for emotions often originate in words for matters that we associate with emotions. In turn, expressions of emotion often begin to be used for politeness and lose some of their original content. Our knowledge about our own and other people’s emotions can turn into fixed phrases that begin to live their own lives. This chapter was inspired by historical semantic research into English words for emotions, but it also discusses Present-day English. Those findings are then also compared with some research on other languages.