This book gives a lucid and up-to-date overview of language change, discussing where our evidence about language change comes from, how and why changes happen, and how languages begin and end. It considers both changes that occurred long ago, and those currently in progress. This substantially revised third edition includes two new chapters on change of meaning and grammaticalization. New sections have been added to other chapters, as well as over 150 new references. The work remains nontechnical in style and accessible to the reader with no previous knowledge of linguistics.