This specially commissioned volume considers the processes involved in language change and the issues of how they can be modelled and studied. The way languages change offers an insight into the nature of language itself, its internal organisation, and how it is acquired and used. Accordingly, the phenomenon of language change has been approached from a variety of perspectives by linguists of many different orientations. This book brings together an international team of leading figures from different areas of linguistics to re-examine some of the central issues in this field and also to discuss new proposals. The volume is arranged into sections - including grammaticalisation, the typological perspective, the social context of language change and contact-based explanations. It seeks to cover the subject as a whole, bearing in mind its relevance for the general analysis of language, and will appeal to a broad international readership.