CHAPTER 1 INTRODUCTION 1.1 Background to the Study 1.2 Outline of the Book CHAPTER 2 DISCOURSE MARKERS Introduction 2.1 Definitions of Discourse Markers 2.2 From Semantics to pragmatics-a polysemous account 2.3 Previous Studies on English Discourse Markers CHAPTER 3 SOCIOLINGUISTIC VARIATION AND PRAGMATICS Introduction 3.1 Sociolinguistic variation studies 3.2 Discourse markers in variational pragmatics 3.3 Gaps in the Literature 3.4 Three discourse markers-well,you know,I think 3.5 Textual and interpersonal functions 3.6 Research questions CHAPTER 4 METHODOLOGY Introduction 4. 1 Methods used to investigate sociolinguistic variation of discourse markers 4.2 Corpus-based sociolinguistic variation studies 4.3 The BNCweb Query System 4.4 The social stratification of individual speakers 4.5 The definition of positions and functions 4.6 Data collection tools used in the present study CHAPTER 5 WELL Introduction 5.1 Descriptions of well 5.2 Sociolinguistic variation of well in the BNC 5.3 Well in Native and Non-native Dyads 5.4 Conclusions CHAPTER 6 YOU KNOW Introduction 6.1 Descriptions of you know 6.2 Sociolinguistic Variation of You know in the BNC 6.3 You know in native and non-native dyads 6.4 Conclusions CHAPTER 7 I THINK Introduction 7.1 Descriptions of I think 7.2 Sociolinguistic Variation of I think in the BNC 7.3 I think in native and non-native dyads 7.4 Conclusions CHAPTER 8 CONCLUSIONS 8.1 Summary of the findings 8.2 Contributions to the Field 8.3 Limitations and Suggestions for Future Research REFERENCES APPENDIX 1 ROLE-PLAY SCENARIO APPENDIX 2 ROLE-PLAY CONSENT FORM APPENDIX 3 ROLE-PLAY FEEDBACK FORM APPENDIX 4 TRANSCRIPTION CONVENTIONS