| Acknowledgement | 第1-6页 |
| 摘要 | 第6-7页 |
| Abstract | 第7-11页 |
| List of Tables and Figures | 第11-12页 |
| Chapter 1 Introduction | 第12-16页 |
| ·Research Background and Rationale for the Study | 第12-13页 |
| ·Research Questions and Significance | 第13-14页 |
| ·The General Organization of the Thesis | 第14-16页 |
| Chapter 2 Literature Review | 第16-34页 |
| ·Theory of Probabilistic Grammar | 第16-21页 |
| ·Introduction of Probabilistic Grammar | 第16-18页 |
| ·Development of Probabilistic Grammar | 第18-21页 |
| ·Different Approaches in the Studies of Modality | 第21-24页 |
| ·Modality Studies in SFL | 第24-32页 |
| ·The Systemic Network of Modality | 第24-29页 |
| ·Studies of Modality Abroad and at Home | 第29-32页 |
| ·The Connection of SFL and Corpus Linguistics | 第32-34页 |
| Chapter 3 Research Design | 第34-39页 |
| ·FLOB Corpus and Analytical Tool | 第34页 |
| ·Rationale for the Scope and Data of Research | 第34-36页 |
| ·Data Sorting Procedures | 第36-39页 |
| Chapter 4 Corpus Findings and Discussions | 第39-68页 |
| ·Probabilistic Distributions of Modality System in Three Genres | 第39-52页 |
| ·Modality Types | 第42-47页 |
| ·Overall Distributions of Modality Type | 第42-44页 |
| ·Skewed Probabilistic Profile of Modality Type | 第44-47页 |
| ·Modality Orientation | 第47-49页 |
| ·Overall Distributions of Modality Orientation | 第47-48页 |
| ·Skewed Probabilistic Profile of Modality Orientation | 第48-49页 |
| ·Modality Value | 第49-52页 |
| ·Overall Distributions of Modality Value | 第49-50页 |
| ·Skewed Probabilistic Profile of Modality Value | 第50-52页 |
| ·The Functions of Different Options in the System of Modality | 第52-66页 |
| ·Discussion in Modality Type | 第52-58页 |
| ·Discussion in Modality Orientation | 第58-62页 |
| ·Discussion in Modality Value | 第62-66页 |
| ·Modality and Genre Variation | 第66-68页 |
| Chapter 5 Conclusion | 第68-72页 |
| ·Major Findings | 第68-70页 |
| ·Implications | 第70-71页 |
| ·Limitations of the Thesis | 第71页 |
| ·Suggestions for Further Study | 第71-72页 |
| Bibliography | 第72-76页 |
| Papers Published During the Study for M.A.Degree | 第76页 |
