Language functions refer to the purposes for which language is used, such as communicating formally or informally. The tone used also depends on the function. For example, when Peter lent money to Carlos and wants it back after a month, there are polite and strong ways for Peter to phrase his request to borrow the money back, ranging from a polite question to a more demanding tone using words like "must" or a short, direct phrase.

1. LANGUAGE FUNCTIONS
Language functions refer to the purposes in
which we use language when we say or write
something. We use language for a variety of
formal and informal purposes. Also, it
sometimes depends on what tone we adopt to
communicate something.

2. For example:
Peter lent some money to Carlos for two days and one month later. Peter says:
Polite
Strong
 Carlos please, can you borrow my money?
 I want you borrow my money.
 I think that you must borrow my money.
 It would be a good idea if you borrow my money.
 My money, right now, OK?