This book sets up a consistent theoretical and terminological framework for the study of the phenomena that are commonly subsumed under the terms transitivity, valency, and voice. These three concepts are at the heart of the most basic aspects of clausal structure in any language; however, there is considerable cross-linguistic variation in the constraints on how verbs combine with noun phrases that refer to participants in the event that they denote or to the circumstances of the event. In this book, Denis Creissels explores and accounts for the extent of this cross-linguistic variation, capturing its regularities and examining the historical phenomena that have resulted in the emergence of constructions and markers. The novel framework developed in the book allows similar phenomena to be identified across typologically diverse languages, and facilitates systematic comparison of the manifestations of these phenomena in the grammars of individual languages.