The teacher decides what methodology or approach to use depending on the aims of the lesson and the learners in the group. Almost all modern course books have a mixture of approaches and methodologies.
The class starts with an inductive activity with learners identifying the different uses of synonyms of movement using a reading text. They then practise these using TPR. In another class the input is recycled through a task-based lesson, with learners producing the instructions for an exercise manual.
In the classroom
A typical lesson might combine elements from various sources such as TPR and TBL (the examples); the communicative approach, e.g. in communication gap activities; the lexical approach, e.g. focusing on lexical chunks in reading; and the structural-situational approach, e.g. establishing a clear context for the presentation of new structures.