| Acknowledgements | 第1-6页 |
| Abstract (in English) | 第6-8页 |
| Abstract (in Chinese) | 第8-12页 |
| Chapter One Introduction | 第12-18页 |
| ·Research Background | 第12-14页 |
| ·Significance of the Study | 第14-15页 |
| ·Research Questions | 第15页 |
| ·Organization of the Thesis | 第15-18页 |
| Chapter Two Literature Review | 第18-26页 |
| ·Definition of Hedges | 第18-19页 |
| ·Studies of Hedges Abroad | 第19-23页 |
| ·Prince et al.'s Model | 第19-21页 |
| ·Salager-Meyer's Model | 第21-22页 |
| ·Hyland's Model | 第22-23页 |
| ·Studies of Hedges At Home | 第23-26页 |
| ·Wu Tieping's Model | 第23-24页 |
| ·He Ziran's Model | 第24-25页 |
| ·Chen Linhua and Li Fuyin's Model | 第25-26页 |
| Chapter Three Theoretical Framework | 第26-36页 |
| ·Pragmatics | 第26-36页 |
| ·Grice's Cooperative Principle (CP) | 第27-30页 |
| ·Leech's Politeness Principle (PP) | 第30-31页 |
| ·Brown and Levinson's Face Theory | 第31-36页 |
| Chapter Four Methodology | 第36-40页 |
| ·The Criteria for Data Source Selection | 第36页 |
| ·The Description ofthe Two Corpora | 第36-38页 |
| ·Data Retrieval | 第38-40页 |
| ·The Tools Used for Data Retrieval | 第38页 |
| ·List of Hedges for Data Retrieval | 第38-40页 |
| Chapter Five Data Analysis | 第40-60页 |
| ·The Analysis of the Overall Frequencies of Hedges in the Two Corpora | 第40-41页 |
| ·Distribution of Four Sub-types of Hedges in the Two Corpora | 第41-42页 |
| ·Similar Uses of Hedges in the Two Corpora | 第42-43页 |
| ·Different Uses of Hedges in the Two Corpora | 第43-46页 |
| ·Different Uses of Adaptors in the Two Corpora | 第43-44页 |
| ·Different Uses of Rounders in the Two Corpora | 第44-45页 |
| ·Different Uses of Plausibility Shields in the Two Corpora | 第45-46页 |
| ·Different Uses of Attribution Shields in the Two Corpora | 第46页 |
| ·Reasons for the Different Uses of Hedges in the Two Corpora | 第46-60页 |
| ·Different Uses Caused by Genre | 第47-50页 |
| ·Different Uses Caused by Objective | 第50-54页 |
| ·Different Uses Caused by Functions | 第54-60页 |
| Chapter Six Conclusion | 第60-66页 |
| ·Main Findings of the Study | 第60-62页 |
| ·Implications of the Study | 第62-63页 |
| ·Implications of the Hedge Use and Awareness | 第62页 |
| ·Implications of Pedagogy | 第62-63页 |
| ·Limitations of the Study | 第63-64页 |
| ·Suggestions for Further Study | 第64-66页 |
| Bibliography | 第66-72页 |
