The advantages of TBL
Task-based learning has some clear advantages
Unlike a PPP approach, the students are free of language control. In all three stages they must use all their language resources rather than just practising one pre-selected item.
A natural context is developed from the students' experiences with the language that is personalised and relevant to them. With PPP it is necessary to create contexts in which to present the language and sometimes they can be very unnatural.
The students will have a much more varied exposure to language with TBL. They will be exposed to a whole range of lexical phrases, collocations and patterns as well as language forms.
The language explored arises from the students' needs. This need dictates what will be covered in the lesson rather than a decision made by the teacher or the coursebook.
It is a strong communicative approach where students spend a lot of time communicating. PPP lessons seem very teacher-centred by comparison. Just watch how much time the students spend communicating during a task-based lesson.
It is enjoyable and motivating.