| 摘要 | 第4-5页 |
| ABSTRACT | 第5-6页 |
| Chapter One Introduction | 第9-16页 |
| 1.1 Background of the Thesis | 第9-11页 |
| 1.2 Significance | 第11-12页 |
| 1.3 Data Collection | 第12-13页 |
| 1.4 Research Questions and Methodology | 第13-14页 |
| 1.5 Organization of the Thesis | 第14-16页 |
| Chapter Two Literature Review | 第16-19页 |
| 2.1 Relevant Studies on the American Presidential Campaign Speeches | 第16-18页 |
| 2.2 Relevant Studies on Vagueness in the American Presidential Campaign Speeches | 第18-19页 |
| Chapter Three Theoretical Framework | 第19-23页 |
| 3.1 A Brief Introduction to Adaptation Theory | 第19-20页 |
| 3.2 Four Key Concepts of Adaptation Theory for This Investigation | 第20-23页 |
| 3.2.1 Contextual Correlates of Adaptability | 第21-22页 |
| 3.2.2 Structural Objects of Adaptability | 第22页 |
| 3.2.3 Dynamics of Adaptability | 第22页 |
| 3.2.4 Salience of the Adaptation Processes | 第22-23页 |
| Chapter Four Vagueness in the American Presidential Campaign Speeches and Its Adaptationto Contexts | 第23-50页 |
| 4.1 A Case Study of the Apparent Appearance of Vagueness | 第23-29页 |
| 4.1.1 Proportion of Vagueness in the Selected Speeches | 第24-26页 |
| 4.1.2 Frequency of Vague Words in the Selected Speeches | 第26-29页 |
| 4.2 Vagueness in Different Linguistic Levels | 第29-44页 |
| 4.2.1 Vagueness in Lexical Level | 第29-37页 |
| 4.2.2 Vagueness in Syntactic Level | 第37-40页 |
| 4.2.3 Vagueness in Discourse Level | 第40-44页 |
| 4.3 Adaptation to Contexts of the American Presidential Campaign Speeches | 第44-50页 |
| 4.3.1 Adaptation to Mental World | 第44-46页 |
| 4.3.2 Adaptation to Social world | 第46-47页 |
| 4.3.3 Adaptation to Physical World | 第47-50页 |
| Chapter Five Pragmatic Functions of Vagueness in the American Presidential CampaignSpeeches | 第50-62页 |
| 5.1 Pragmatic Functions Achieved by Adapting to Mental World | 第50-53页 |
| 5.1.1 Arousing Audiences’ Feelings | 第50-52页 |
| 5.1.2 Creating and Maintaining Harmonious Foreign Atmosphere | 第52-53页 |
| 5.2 Pragmatic Functions Achieved by Adapting to Social World | 第53-56页 |
| 5.2.1 Evoking Audiences’ Oppositions to the Opponent | 第53-55页 |
| 5.2.2 Strengthening Objectivity | 第55-56页 |
| 5.3 Pragmatic Functions Achieved by Adapting to Physical World | 第56-59页 |
| 5.3.1 Seeking Acceptation from Local People | 第57-58页 |
| 5.3.2 Avoiding Being Criticized | 第58-59页 |
| 5.4 Comparison between Pragmatic Functions of Vagueness in the American PresidentialCampaign Speeches and Those in Daily Communication | 第59-62页 |
| 5.4.1 Pragmatic Functions of Vagueness in Daily Communication | 第59-61页 |
| 5.4.2 Similarities and Differences | 第61-62页 |
| Chapter Six Conclusion | 第62-66页 |
| 6.1 Summary | 第62-64页 |
| 6.2 Limitations and Suggestions for Further Researches | 第64-66页 |
| Reference | 第66-69页 |
| Appendix | 第69-73页 |
| Acknowledgements | 第73页 |
