This paper explores the relation between interrogative, a category of grammatical form, and question, a category of meaning. Interrogative contrasts with declarative, imperative, etc., in the system of clause type (not sentence type); a question defines a set of answers. Two kinds of interrogative are distinguished, closed and open - though in some languages they may be distinct primary classes. Three kinds of question are distinguished according to the way the set of answers is defined: polar, alternative and variable questions; another dimension distinguishes information from direction questions. Mismatches between interrogatives and questions are found in the areas of coordination, parentheticals, echoes and questions signalled only pros...