Task-based Language Teaching (TBLT) has been gaining momentum around the world during the past twenty years. However, particularly lacking in the body of available publications on TBLT is empirical evidence of the actual activity, interaction and learning processes that tasks give rise to in real classrooms. This volume compiles a number of studies that describe what learners and teachers, in various educational contexts, actually do when they are asked to perform tasks as part of their regular classroom activity. As such, the volume provides valuable new insights into the implementation of task-based language teaching and vividly illustrates how classroom practice can inform future theory-building and research on TBLT. All the chapters in this book are based on papers that were presented during the first International Conference on Task-Based Language Teaching, which was organised in Leuven in September 2005 by the Centre for Language and Education of the Katholieke Universiteit Leuven.