The book revisits the notion of deontic modality from the perspective of an understudied category in the modal domain, viz. adjectives. On the basis of synchronic and diachronic corpus studies, it analyses the semantics of English adjectives like essential and appropriate, and uses this to refine traditional definitions of deontic modality, which are mainly based on the study of modal verbs. In a first step, it is shown that the set of meanings expressed by extraposition constructions with deontic adjectives is quite different from the set of meanings identified in the...