Why do people sometimes leave off the ends of words when they speak? Is it sloppiness, progress, or inevitable erosion? This book attempts to answer such questions by giving a lucid and up-to-date overview of language change. It discusses where our evidence about language change comes from, how and why changes happen, and how and why languages begin and end. It considers not only changes which occurred many years ago, but also those currently in progress. It does this within the framework of one central question - is language change a symptom of progress or decay? It concludes that language is neither progressing nor decaying, but that an understanding of the factors causing change is essential for anyone involved with language alteration. For this substantially revised and enlarged second edition Jean Aitchison has included details of recent research on a number of key topics, and also discusses data from a wider variety of languages: but the work remains non-technical in style and accessible to the reader with no previous knowledge of linguistics.