| Abstract | 第1-6页 |
| 摘要 | 第6-9页 |
| Introduction | 第9-12页 |
| The reasons for present study | 第9-10页 |
| Overview of the thesis | 第10-12页 |
| 1 Literature Review | 第12-32页 |
| ·Metafunctions of language | 第12-13页 |
| ·Interpersonal meaning | 第13-17页 |
| ·Modality | 第17-28页 |
| ·Features of Question-Answer section in “215t Century Cup”National English Speaking Competition | 第28-32页 |
| 2 Research Methodology | 第32-35页 |
| ·Research purpose and hypothesis | 第32-33页 |
| ·Data collection | 第33-34页 |
| ·Analyzing methods | 第34-35页 |
| 3 Research Findings | 第35-50页 |
| ·Frequencies of modal expressions in samples | 第35-37页 |
| ·Modal expressions in modalization and modulation | 第37-47页 |
| ·Co-occurrence of modal expressions | 第47-49页 |
| ·Summary | 第49-50页 |
| 4 Discussion | 第50-64页 |
| ·Modality: a way to be objective | 第50-51页 |
| ·Modality : as politeness strategy | 第51-60页 |
| ·Modality: as an interactional strategy | 第60-63页 |
| ·Summary | 第63-64页 |
| Conclusion | 第64-67页 |
| Acknowledgements | 第67-68页 |
| References | 第68-73页 |
| Appendix I Published Paper during MA study | 第73-74页 |
| Appendix II Samples of Corpus Data | 第74-92页 |
