This is the first monograph to provide a detailed account of the fundamental changes which have recently affected-and which still are affecting-the system of English auxiliaries.

This study improves our understanding of both the present and the past of a central domain of the English grammar and will thus appeal to historical linguists and linguists focusing on present-day English alike. On account of its innovative approach and empirical scope, it will serve as the standard reference work on English modal constructions. The book is also valuable for its proposal of two prototype-oriented models for the emergence of a new verbal category. While it addresses primarily an area of English grammar, as a study in grammaticalization it also provides hypotheses (e.g. regarding reanalysis and unidirectionality) which can be tested in work on grammatical change of any other language. On a higher level of abstraction, then, this book offers new insights to linguists and advanced students interested in any one of the following areas: grammaticalization (phonological, morphological, syntactic and semantic change), modality, functionalism, corpus linguistics, prototype theory, iconicity, sociolinguistics and stylistics.