| Abstract | 第1-6页 |
| 摘要 | 第6-9页 |
| Introduction | 第9-12页 |
| 1 Literature Review | 第12-23页 |
| ·Definitions of hedges | 第12-14页 |
| ·Categorizations of hedges | 第14-17页 |
| ·Cooperative Principle and hedges | 第17-19页 |
| ·Previous studies of the functions of hedges | 第19-23页 |
| 2 Research Methodology | 第23-26页 |
| ·Research questions | 第23页 |
| ·Data collection | 第23-24页 |
| ·Data analysis | 第24-26页 |
| 3.R esults and Discussion | 第26-51页 |
| ·Frequency and distribution of different types of hedges | 第26-28页 |
| ·Analysis of hedges from the perspective of Cooperative Principle | 第28-44页 |
| ·Pragmatic functions of hedges in the 2008 American Presidential Debate | 第44-51页 |
| Conclusion | 第51-54页 |
| Acknowledgements | 第54-55页 |
| References | 第55-59页 |
| AppendixⅠ Hedges in the 2008 American Presidential debates | 第59-61页 |
| AppendixⅡ Excerpt from the first presidential debate | 第61-67页 |
