| Abstract | 第1-7页 |
| 摘要 | 第7-12页 |
| Introduction | 第12-18页 |
| Chapter One Literature Review | 第18-36页 |
| ·Overview of Vague Language | 第18-30页 |
| ·Different Definitions of Vague Language | 第18-20页 |
| ·Sources of Vague Language | 第20-22页 |
| ·Relations of Some Related Terms | 第22-26页 |
| ·Review of Previous Studies of Vague Language | 第26-30页 |
| ·Overview of Bad-News Business English Letters | 第30-36页 |
| ·Nature of Bad-News Business English Letters | 第31-32页 |
| ·Types of Bad-News Business English Letters | 第32-33页 |
| ·Writing Strategies of Bad-News Business English Letters | 第33-34页 |
| ·Previous Studies of Bad-News Business English Letters | 第34-36页 |
| Chapter Two Theoretical Foundation | 第36-48页 |
| ·Adaptation Theory | 第36-43页 |
| ·Three Properties of Language Use | 第37-39页 |
| ·Four Aspects of Adaptation Theory | 第39-43页 |
| ·Politeness Principle | 第43-48页 |
| Chapter Three Vague Language in Bad-News Business English Letters | 第48-78页 |
| ·Linguistic Realization of Vague Language in Bad-News Business English Letters | 第48-61页 |
| ·Lexical Vagueness | 第49-53页 |
| ·Syntactic Vagueness | 第53-55页 |
| ·Hedges | 第55-59页 |
| ·Vagueness by Implicature | 第59-61页 |
| ·General Situations of Employment of Vague Language in Bad-News Business English Letters | 第61-65页 |
| ·Objective Employment of Vague Language | 第61-63页 |
| ·Subjective Employment of Vague Language | 第63-65页 |
| ·Pragmatic Functions of Vague Language in Bad-News Business English Letters | 第65-78页 |
| ·Positive Pragmatic Functions of Vague Language | 第66-75页 |
| ·Negative Function of Vague Language | 第75-78页 |
| Chapter Four The Adaptation of Vague Language in Bad-News Business English Letters | 第78-112页 |
| ·Linguistic Choices of Vague Language—Result of Linguistic Adaptation | 第78-81页 |
| ·The Dynamics of Adaptation | 第81-83页 |
| ·Adaptation to the Letter Writer and the Letter Reader | 第83-87页 |
| ·Adaptation to the Writer's Voices | 第83-85页 |
| ·Adaptation to the Reader | 第85-87页 |
| ·Adaptation to the Psychological Motivations | 第87-99页 |
| ·Adaptation to the Writer's Intention | 第88-90页 |
| ·Adaptation to the Writer's Emotion | 第90-92页 |
| ·Adaptation to the Reader's Emotion | 第92-94页 |
| ·Adaptation to the Reader's Wishes | 第94-96页 |
| ·Adaptation to Other Psychological Motivations-Elasticity in Time, Quantity and Attitude | 第96-99页 |
| ·Adaptation to the Social World | 第99-107页 |
| ·Adaptation to the Social Positions | 第100-101页 |
| ·Adaptation to the Social Distance | 第101-103页 |
| ·Adaptation to the Communicator's Profession | 第103-105页 |
| ·Adaptation to the Cultural Conventions | 第105-107页 |
| ·Adaptation to the Physical World | 第107-112页 |
| ·Adaptation to Time | 第108-109页 |
| ·Adaptation to Space | 第109-112页 |
| Conclusion | 第112-118页 |
| Bibliography | 第118-124页 |
| Acknowledgements | 第124-126页 |
