This book is an introduction to the study of word-formation, that is, the ways in which new words are built on the bases of other words (e.g. happy-happy-ness), focusing on English. The book's didactic aim is to enable students with little or no prior linguistic knowledge to do their own practical analyses of complex words. Readers are familiarized with the necessary methodological tools to obtain and analyze relevant data and are shown how to relate their findings to theoretical problems and debates. The book is not written in the perspective of a particular theoretical framework and draws on insights from various research traditions, reflecting important methodological and theoretical developments in the field. It is a textbook directed towards university students of English at all levels. It can also serve as a source book for teachers and advanced students, and as an up-to-date reference concerning many word-formation processes in English.