Until recently, research studies on task-based language teaching (TBLT) have concentrated on the effective syllabus design at the context of practical activities. However, there is little research on the extent to how the instruction in classrooms is practiced, related with a focus on target forms. The present book explores the investigation of adaptation of TBLT to a task design of writing tasks, on the basis of instructed forms explicitly. Moreover, this book investigates the extent to which target tasks are associated with task-related factors and learner-related factors, in terms of accomplishments of writing tasks to write an email and to write a narrative story. The results of data analyses revealed that target forms were not acquired and primarily paraphrased as the main learning strategy of learners. Reading this book will be very meaningful to teachers to see how TBLT and writing can be related well to develop language usages and proficiency of L2.