The design of a task-based lesson involves consideration of the stages or components of a lesson that has a task as its principal component. Various designs have been proposed(e. g. Estaire and Zanon 1994; Lee 2000; Prabhu 1987; Skehan 1996; Willis 1996). However they all have in common three principal phases, which are shown in Figure 1. These phases reflect the chronology of a task-based lesson. Thus, the first phase is ‘pre-task’ and concerns the various activities that teachers and students can undertake before they start the task, such as whether students are given time to plan the performance of the task. The second phase, the ‘during task’phase, centres around the task itself and affords various instructional options, including whether students are required to operate under time-pressure or not. The final phase is ‘post-task’ and involves procedures for following-up on the task performance. Only the ‘during task’ phase is obligatory in task-based teaching. Thus, minimally, a task-based lesson consists of the students just performing a task. Options selected from the ‘pre-task’or ‘post-task’phases are non- obligatory but, as we will see, can serve a crucial role in ensuring that the task performance is maximally effective for language development.