This book investigates the way grammar deals with the representation of aspectual (aktionsart) concepts, focusing on issues of the lexicon-syntax interface. The authors' analyses of this interface advances our understanding of the role that syntax plays in determining verbal meaning, aspectual interpretation, and thematic information. Various theories are developed in this collection, including those that take as their starting point the lexical-syntactic framework of Hale and Keyser, prominent among which is the chapter by Hale and Keyser themselves. Under this view, syntactic structure is projected from lexical roots or meaning components. Other contributions view event structure in terms of feature projections. Yet others examine lexical restrictions on syntactic projection. The articles offer different approaches to the manner of representation of aspectual notions like telicity, duration, cause, and change: that the information is realized in functional projections and light verb projections; that the information cannot be properly represented syntactically; and even that information like telicity is not relevant to aspectual classification at all. By examining different phenomena in a cross-linguistic perspective, this book develops insights into the general theoretical question of universal grammar and acquisition, as well as into the specific nature of the lexicon-syntax interface.