Grammar is central to the teaching and learning of languages. It is also one of the more difficult aspects of language to teach well.

Many people, including language teachers, hear the word "grammar" and think of a fixed set of word forms and rules of usage. They associate "good" grammar with the prestige forms of the language, such as those used in writing and in formal oral presentations, and "bad" or "no" grammar with the language used in everyday conversation or used by speakers of nonprestige forms.

Language teachers who adopt this definition focus on grammar as a set of forms and rules. They teach grammar by explaining the forms and rules and then drilling students on them. This results in bored, disaffected students who can produce correct forms on exercises and tests, but consistently make errors when they try to use the language in context.

Other language teachers, influenced by recent theoretical work on the difference between language learning and language acquisition, tend not to teach grammar at all. Believing that children acquire their first language without overt grammar instruction, they expect students to learn their second language the same way. They assume that students will absorb grammar rules as they hear, read, and use the language in communication activities. This approach does not allow students to use one of the major tools they have as learners: their active understanding of what grammar is and how it works in the language they already know.

The communicative competence model balances these extremes. The model recognizes that overt grammar instruction helps students acquire the language more efficiently, but it incorporates grammar teaching and learning into the larger context of teaching students to use the language. Instructors using this model teach students the grammar they need to know to accomplish defined communication tasks.