What are language functions?

When you are trying to choose the best way to express yourself in a particular situation, you must keep in mind what you are doing with your language. Are you introducing someone, describing something, (dis) agreeing with someone, asking for/giving permission or what? These are called language functions. Language functions, in other words, are the purposes for which we speak or write.A context plays a very important role in learning a concept. To enable the learners to understand the use of a language function, it is generally presented through a dialogue, and then the practice of that particular language function is given.

How to classify the expressions under a language function?

The expressions under a language function are classified according to the three
levels of formality:

1.neutral
2.informal 3.formal.
We can, however, for our school learners, just maintain two levels: formal and informal.