Language functions, such as promising, inviting, predictions, are highly emphasized over specific linguistic structures. Various language forms are introduced for each function and the learning purpose is mainly to reinforce language functions. In this sense, simple past tense is probably served as the functions like story-telling, narrating events, asking for a description of someone or something.
Students are provided with a series of activities that have the following characteristics:
1) The meanings conveyed should be previously unknown to everybody. That is to say, an information gap should exist when one person exchanges some information that the other person does not know. For example, two students talk about their birthday experience by asking and answering the following questions:
How did you celebrate your birthday?
Where did you spend the day and with whom did you spend it?
Was it fun?
2) The speaker has a choice of what he/she will say.
3) It also involves meaning negotiation. The listener has an opportunity to provide the speaker with certain feedback.
Larsen-Freeman, D., & Anderson, M. (2011). Techniques & Principles in Language Teaching (pp. 115-130). Oxford: Oxford University Press.
Littlewood, W. (2004). Task-Based Learning of Grammar. Hong Kong: HKBU.