| Acknowledgements | 第1-4页 |
| 摘要 | 第4-5页 |
| Abstract | 第5-8页 |
| Figures and Tables | 第8-9页 |
| Chapter One Introduction | 第9-12页 |
| Chapter Two Discourse Markers | 第12-20页 |
| ·The functions of language | 第12-13页 |
| ·Discourse markers | 第13-20页 |
| ·The general properties of discourse markers | 第13-18页 |
| ·Summary | 第18-20页 |
| Chapter Three Past Researches | 第20-31页 |
| ·The grammaticalization analysis of discourse markers | 第20-22页 |
| ·The analysis on semantics about discourse markers | 第22-25页 |
| ·The analysis of discourse markers based on the Speech-Act-Theory | 第25-30页 |
| ·Speech-Act-Theory | 第25-26页 |
| ·Illocution analysis of these markers | 第26-30页 |
| ·Summary | 第30-31页 |
| Chapter Four the Discourse Marker I suppose | 第31-69页 |
| ·The grammaticalization of discourse marker I suppose | 第31-41页 |
| ·Layering | 第32-35页 |
| ·Divergence | 第35-36页 |
| ·Persistence | 第36-37页 |
| ·De-categorialization | 第37-40页 |
| ·Specialization | 第40-41页 |
| ·The meaning conveyed by the discourse marker I suppose | 第41-48页 |
| ·The core meaning of I suppose | 第43-45页 |
| ·The pragmatic meaning of I suppose | 第45-48页 |
| ·Illocutionary force of the discourse marker I suppose | 第48-60页 |
| ·Illocutionary force of the marker in sentence-initial position | 第52-53页 |
| ·Illocutionary force of the marker in sentence-final position | 第53-56页 |
| ·The distribution of discourse marker I suppose | 第56-60页 |
| ·Pragmatic functions of discourse marker I suppose | 第60-69页 |
| ·Politeness | 第61-62页 |
| ·Mitigation of discourse marker I suppose | 第62-69页 |
| ·Speaker’s commitment | 第63-65页 |
| ·Illocutionary forces assigned to the addressee | 第65-69页 |
| Chapter Five Conclusion | 第69-72页 |
| 1) The marker I suppose is a grammaticized form. | 第69页 |
| 2) The meaning of the marker tends to be more connected with the speaker’s psychological state. | 第69-70页 |
| 3) It is one of the devices for the speaker to mitigate the unwanted consequence of what he or she expresses, showing politeness to the hearer. | 第70-72页 |
| Bibliography | 第72-79页 |
