The two chapters in this part of the book are intended to provide a foundation for the subsequent parts.

Chapter 1 is written for this book. In it I provide a brief historical sketch of how task-based language teaching (TBLT) has developed, tracing its origins in a strong version of communicative language teaching and in early second language acquisition research that pointed to the existence of natural orders and sequences of acquisition that are to a large extent impermeable to the infl uence of direct language instruction. I then consider how the early version of TBLT evolved over time, as it drew increasingly on general educational principles as well as second language acquisition (SLA). I emphasize that TBLT is not to be seen as monolithic but as quite varied, refl ecting diff erences in how its advocates view the design of syllabuses and the ways in which tasks can be most eff ectively implemented to facilitate acquisition. Underlying these diff erences, however, is the common assumption that instruction should aim at facilitating rather than controlling and directing acquisition, which can be best achieved by using tasks.

Chapter 2 was first published in 2000. It introduces the theoretical underpinnings of TBLT. It contrasts two theoretical inputs. Cognitive theories point to the need to design and implement tasks in ways that connect with the cognitive processes involved in L2 production and acquisition. Sociocultural theory points to the need to acknowledge the diff erence between task-as-workplan and task-as-process and that how learners perform a task (i.e. the task-as-process) will always be – to some extent at least – unpredictable.