Can you imagine language without being communicative? Can you think about something alive that does not communicate anything? Well, let me guess… your answers are probably “NO!” every kind of language communicates any kind of message and each message has its own meaning which is conveyed by people of a society. Therefore, I assume (and support myself on functionalist theories) that the main purpose language may have is TO COMMUNICATE. So, in my opinion a language class should be based on communication, even more if it is an EFL class, since class-time is almost the only one opportunity students have for practicing the target language.
Besides, language changes according to the context. This makes more important for students to have the cultural knowledge required for language accuracy. Of course, language components are very important for language proficiency but these can be taught in a different way paying more attention to language usage than structures. And notice that teaching structures, rules, pronunciation, among others IS IMPORTANT because every language, even every dialect has its own behavior and rules, but once a person can communicate, transmit a message or idea, that person is accomplishing the main purpose of language teaching/learning.This is the main tenet of the Communicative Language Teaching approach (maybe the most accepted approach at the moment) make people communicate according to the context with good proficiency and appropriate accuracy in the target language.

