Moral Modality In English

Modality can be found in almost all the languages of the world. Modality is the speaker's opinion and attitude on the factuality of a proposition or an event. In this thesis, with reference to basic semantic theories and concepts, I talk about the history of modality study, mood and modal system; make thorough study on deontic modality in English language; and analyze deontic expressions in English texts of different styles. First, I introduce the history of modality study, foreign linguists' research and achievements in this field and analyze mood and modal system. Then, based on Plamer's modal system, I specially talk about deontic modality in English language and find out some semantic and grammatical features that make deontic modality a distinct category. Finally, I make a thorough study of modality in political, legal, news and academic texts, which shows that deontic modality use is closely related to the style of texts. Deontic modality expresses permission, possibility, obligation and prohibition in political and legal texts, while possibility, volition and futurity in news and academic texts. So by analyzing the distribution of deontic modality in different texts we can find out more subtle meanings and functions of modalities and unearth more features that categorize texts.