| Abstract (Chinese) | 第4-6页 |
| Abstract | 第6-8页 |
| List of Abbreviations | 第11-13页 |
| Introduction | 第13-17页 |
| 1 Background of the Study | 第13-14页 |
| 2 Purpose of the Study | 第14-15页 |
| 3 Significance of the Study | 第15页 |
| 4 Organization of the Thesis | 第15-17页 |
| Chapter One Halliday's Modality Theory | 第17-24页 |
| 1.1 Definitions of Modality | 第17-18页 |
| 1.2 Functions of Modality | 第18-19页 |
| 1.3 Types of Modality | 第19-21页 |
| 1.4 Orientation of Modality | 第21-22页 |
| 1.5 Summary | 第22-24页 |
| Chapter Two Literature Review | 第24-33页 |
| 2.1 Previous Studies on Modality | 第24-28页 |
| 2.1.1 Studies on Modality Abroad | 第24-26页 |
| 2.1.2 Studies on Modality at Home | 第26-28页 |
| 2.2 Previous Studies on Modal Adverbs | 第28-31页 |
| 2.2.1 Studies on Modal Adverbs Abroad | 第28-30页 |
| 2.2.2 Studies on Modal Adverbs at Home | 第30-31页 |
| 2.3 Summary | 第31-33页 |
| Chapter Three Research Methodology | 第33-40页 |
| 3.1 Research Questions | 第33页 |
| 3.2 Data Collection | 第33-34页 |
| 3.3 Tools | 第34-35页 |
| 3.3.1 AntConc | 第34-35页 |
| 3.3.2 SPSS 23.0 | 第35页 |
| 3.3.3 Excel | 第35页 |
| 3.4 Methods of Data Analysis | 第35-36页 |
| 3.4.1 Quantitative Method | 第35-36页 |
| 3.4.2 Qualitative Method | 第36页 |
| 3.5 Framework of the Study | 第36-40页 |
| 3.5.1 Classifications of Modal Adverbs Used in the Study | 第36-39页 |
| 3.5.2 Value of Modal Adverbs | 第39-40页 |
| Chapter Four Results and Discussion | 第40-63页 |
| 4.1 Overall Distribution of Modal Adverbs Used between Chinese andAmerican Scholars | 第40-42页 |
| 4.1.1 General Frequency of Modal Adverbs | 第41页 |
| 4.1.2 General Features of the Use of Modal Adverbs | 第41-42页 |
| 4.2 Features of Probability Used between Chinese and American Scholars | 第42-50页 |
| 4.2.1 Frequency of Modal Adverbs for Probability | 第42-46页 |
| 4.2.2 Value of Modal Adverbs for Probability | 第46-50页 |
| 4.3 Features of Usuality Used between Chinese and American Scholars | 第50-57页 |
| 4.3.1 Frequency of Modal Adverbs for Usuality | 第50-52页 |
| 4.3.2 Deduction and Induction of Modal Adverbs for Usuality | 第52-57页 |
| 4.4 Features of Orientation Used between Chinese and American Scholars | 第57-62页 |
| 4.4.1 Frequency of Modal Adverbs for Orientation | 第57-58页 |
| 4.4.2 Subjectivity and Objectivity of Modal Adverbs for Orientation | 第58-62页 |
| 4.5 Summary | 第62-63页 |
| Conclusion | 第63-66页 |
| 1 Major Findings of the Study | 第63-64页 |
| 2 Limitations of the Study | 第64-65页 |
| 3 Implications of the Study | 第65页 |
| 4 Suggestions for Further Study | 第65-66页 |
| Acknowledgements | 第66-67页 |
| Bibliography | 第67-74页 |
| Appendix | 第74页 |
| Appendix Ⅰ | 第74页 |
