Interrogative constructions are the linguistic forms by which questions are expressed. Even though they have played a central role in the development of modern syntactic theory, there exist few syntactic and semantic treatments that provide a comprehensive account of a wide range of interrogative constructions and uses in a single language. This text aims to close the gap in research on this subject. It develops the frameworks of head driven phrase structure grammar and situation semantics, to provide an account that integrates syntactic, semantic and contextual dimensions of interrogatives. The book provides insights about a variety of contentious theoretical issues, including matters of semantic ontology, the quantificational status of wh-phrases, the semantic effect of wh-fronting, the status of constructions in grammatical theory, the integration of illocutionary information in the grammar and the nature of ellipsis resolution in dialogue.