The universal and typological status of the notion of word class — closely related to part-of-speech systems, morphology, syntax and the lexicon-syntax interface — continues to be of major linguistic theoretical interest. The papers included in this volume offer a fresh look at the variety of current theoretical and descriptive approaches to word class issues, and present original analyses and new data from a number of languages. The primary focus is on methods (including computational ones) and criteria for identifying and representing major word classes and subclasses in specific languages, with considerable attention also directed towards the characterization of the nature and role of minor — or neglected — word classes, including trans-categorization processes. The range of topics and perspectives covered makes this volume of considerable interest to both theoretical linguists and typologists.