| Acknowledgements | 第6-7页 |
| Abstract | 第7-8页 |
| 摘要 | 第9-12页 |
| Chapter One Introduction | 第12-16页 |
| 1.1 Background of the Research | 第12-13页 |
| 1.2 Research Questions | 第13页 |
| 1.3 Data Collection and Research Methods | 第13-14页 |
| 1.4 Organization of the Thesis | 第14-16页 |
| Chapter Two Hedges and Hedging | 第16-26页 |
| 2.1 Defining Hedges and Hedging | 第16-18页 |
| 2.2 Semantic Approaches to Hedges and Hedging | 第18-20页 |
| 2.3 Pragmatic Approaches to Hedges and Hedging | 第20-23页 |
| 2.4 Previous Studies of Hedges and Hedging in Political Discourses | 第23-26页 |
| Chapter Three Adaptation Theory | 第26-35页 |
| 3.1 Historical Background of Adaptation Theory | 第26-27页 |
| 3.2 Key Notions of Adaptation Theory | 第27-33页 |
| 3.2.1 Making Linguistic Choices | 第27-29页 |
| 3.2.2 Properties of Language | 第29-30页 |
| 3.2.3 Four Angles of Adaptation | 第30-33页 |
| 3.3 The Perspective of the Present Study | 第33-35页 |
| Chapter Four Linguistic Realizations of Hedging in American Presidential Debates | 第35-50页 |
| 4.1 Hedging at Lexical Level | 第35-43页 |
| 4.1.1 Adverbs | 第36-39页 |
| 4.1.2 Adjectives | 第39-41页 |
| 4.1.3 Indefinite Pronouns | 第41-42页 |
| 4.1.4 Numerals | 第42-43页 |
| 4.2 Hedging at Syntactical Level | 第43-47页 |
| 4.2.1 Conditionals | 第44-45页 |
| 4.2.2 Quoting Devices | 第45-46页 |
| 4.2.3 Passive Voices | 第46页 |
| 4.2.4 Negative Structures | 第46-47页 |
| 4.3 Hedging at Discourse Level | 第47-50页 |
| Chapter Five Contextual Adaptation of Hedging in American Presidential Debates | 第50-67页 |
| 5.1 Adapting to the Mental World | 第50-60页 |
| 5.1.1 Adapting to the Psychology of Self-protecting | 第51-54页 |
| 5.1.2 Adapting to the Motivation of Enhancing Persuasion | 第54-56页 |
| 5.1.3 Adapting to the Purpose of Constructing a Positive Image | 第56-58页 |
| 5.1.4 Adapting to the Audience's Expectations | 第58-60页 |
| 5.2 Adapting to the Social World | 第60-64页 |
| 5.2.1 Adapting to Social Culture | 第60-61页 |
| 5.2.2 Adapting to Communicative Norms | 第61-64页 |
| 5.3 Adapting to the Physical World | 第64-67页 |
| Chapter Six Conclusion | 第67-70页 |
| 6.1 Major Findings | 第67-68页 |
| 6.2 Significance of the Current Study | 第68页 |
| 6.3 Limitations and Suggestions for Further Investigation | 第68-70页 |
| Bibliography | 第70-74页 |
