Language cannot be understood fully without an awareness of the social context? A-level people help me!?

We have a question "In an interview for emagazine (Aug 1998) Basil Bernstein observed that a significant contribution to linguistics was made by Norman Fairclough because he insists that language cannot be understood fully without an awareness of the social context. Do you think this is true? Argue your case with reference to specific exmaples of spoken language in use." only I don't have my text book and I'm so confused!!! Can someone give me reasons why there is a need for awareness of social context? I need to hand this in tomorrow. We got it today. My teachers are evil.