1[1]Andreas,H.Jucker,Sara W.Smith & Tanja,L.2003.Interactive Aspects of Vagueness in Conversation.Journal of Pragmatics Vol.35.
2[2]Brown,P & Levinson,S.C.1987.Politeness:Some Universals in Language Usaeg.Cambridge:Cambridge University Press.
3[3]Chaudron,C.1988 Second Language Classrooms:Research on Teaching and Learning.Cambridge:Cambridge University Press.
4[4]Crystal,D.&David,D.1975 Advanced Conversional English.London:Longman Ellis,R.1994 The Study of Second Language Acquisition.Oxford:Oxford University Press.
5[5]Sperber,D.&Wilson,D.1986Re]evance:Communication and Cognition.Blackwell Publisher Ltd.