| Abstract | 第1-6页 |
| 摘要 | 第6-9页 |
| Chapter One Introduction | 第9-12页 |
| ·Research Questions | 第9页 |
| ·Significance of the Study | 第9-10页 |
| ·Organization of the Paper | 第10-12页 |
| Chapter Two Literature Review | 第12-20页 |
| ·Vague Language | 第12-17页 |
| ·Defining Vagueness | 第12页 |
| ·Terms Related to Vagueness | 第12-15页 |
| ·Classification of Vague Language | 第15-17页 |
| ·Overview of Previous Research on Vague Language | 第17-20页 |
| ·Previous Research Aboard | 第17-19页 |
| ·Previous Research at Home | 第19-20页 |
| Chapter Three Analytical Theories | 第20-24页 |
| ·Adaptation Theory | 第20-21页 |
| ·Cooperative Principle | 第21-22页 |
| ·Politeness Principle | 第22-24页 |
| Chapter Four Research Methodology | 第24-26页 |
| ·Data Collection | 第24页 |
| ·Quantitative and Qualitative Methods | 第24-26页 |
| Chapter Five Results and Discussion | 第26-49页 |
| ·A Quantitative Analysis of Vague Language in English Business Letters | 第26-39页 |
| ·Vague Language in Sales Letters and Letters for Establishing Business Relations | 第26-28页 |
| ·Vague Language in Enquiries and Offers | 第28-31页 |
| ·Vague Language in Counter-offers and Counter-counter Offers | 第31-33页 |
| ·Vague Language in Orders and Terms of Payment | 第33-35页 |
| ·Vague Language in Insurance and Shipment Letters | 第35-36页 |
| ·Vague Language in Claims and Letters of Apologies | 第36-39页 |
| ·A Qualitative Analysis of Vague Language in English Business Letters | 第39-46页 |
| ·Pragmatic Analysis of Vague Language According to Adaptation Theory | 第40-43页 |
| ·Pragmatic Analysis of Vague Language According to Cooperative Principle | 第43-45页 |
| ·Pragmatic Analysis of Vague Language According to Politeness Principle | 第45-46页 |
| ·Functions of Vague Language in English Business Letters | 第46-49页 |
| ·Enhancing Persuasiveness | 第46-47页 |
| ·Increasing Self-protection | 第47-48页 |
| ·Strengthening Politeness | 第48页 |
| ·Skillfully Retaining Information | 第48-49页 |
| Chapter Six Conclusion | 第49-51页 |
| ·Main Findings | 第49-50页 |
| ·Limitations of the Study | 第50页 |
| ·Suggestions for Further Study | 第50-51页 |
| References | 第51-53页 |
| Appendix | 第53-73页 |
| Acknowledgement | 第73页 |
