Language functions refer to the purposes in which we use language to communicate. We use language for a variety of formal and informal purposes, and specific grammatical structures and vocabulary are often used with each language function. Some examples of language functions include:
Compare and contrast
Persuasion
Asking questions
Expressing likes and dislikes
Cause and effect
Summarizing
Sequencing
Predicting
Agreeing/disagreeing
Greeting people/introductions