“语言是交际的工具，语言教学的最终目的是培养学生以书在或口头方式进行交际的能力。”这既是英语教学大纲的规定，也是我国广大英语教学研究者和教师的共识。社会语言学家费什曼（Ｆｉｓｈｍａｎ）把交际能力概括为：Ｗｈｏｓｐｅａｋｓｗｈａｔｌａｎｇｕａｇｅｔｏｗｈｏ “Language is the communicative tool, and the ultimate goal of language teaching is to develop the ability of students to communicate in the book or verbally.” This is both the stipulation of the English syllabus and the consensus of the majority of English teaching researchers and teachers in our country. Fishman, a sociolinguist, summarizes communicative competence as: Whospeakswhatlanguagetowho