Task-based teaching views learning as taking place holistically and incidentally as learners perform tasks. In a task-based lesson, there is no attempt to specify what language learners will learn. In fact, different students may end up learning different [aspects of a] language as a result of performing the same task. Learners learn naturally by performing tasks and focusing on form while communicating.
Sometimes teachers and students find task-based language teaching threatening because it is so different from the kind of teaching they are used to. As a result, they may resist trying to do task-based language teaching. It is important that students have a clear understanding of how communicative competence in a language is acquired and how performing tasks can help them develop communicative competence.