Advantages
Task-based learning is advantageous to the student because it is more student –centered, allow for more meaningful communication ,and often provides for practical extra –linguistic skill building .Although the teacher may present language in the pre-task ,the student are ultimately free to use what grammar constructs and vocabulary they want. This allows them to use all the language they know and are learning, rather than just the ‘target language’ of the lesson. Furthermore, as the tasks are likely to be familiar to the students (eg: visiting the doctor), students are more likely to be engaged, which may further motivate them in their language learning.
Disadvantages
There have been criticisms that task-based learning is not appropriate as the foundation of a class for beginning students. The major disadvantages for beginning student is that the focus of task-based language learning is on output, when beginning language learners often go through a silent period requiring massive amounts of comprehensible input. Others claim that students are only exposed to certain forms of language, and are being neglected of others, such as discussion or debate. Teachers may want to keep these in mind when designing a task-based learning lesson plan.