| 摘要 | 第1-5页 |
| Abstract | 第5-13页 |
| 1 Introduction | 第13-15页 |
| ·Research Background | 第13页 |
| ·Research Questions | 第13-14页 |
| ·Organization of the Thesis | 第14-15页 |
| 2 Literature Review | 第15-26页 |
| ·Overseas Studies on Null Subjects in L2 Acquisition | 第15-21页 |
| ·The Pro-drop Parameter (Null-subject Parameter) | 第15-17页 |
| ·The Morphological Uniformity Principle | 第17页 |
| ·Discourse-oriented Languages and Sentence-oriented Languages | 第17-18页 |
| ·Studies within the Theoretical Framework of the Minimalist Program | 第18-21页 |
| ·Overseas Studies in L1 and L2 Acquisition concerning the Asymmetry of NuSubjects and Null Objects | 第21-24页 |
| ·Studies in L1 Acquisition concerning the Asymmetry of Null Subjects and Null Objects | 第21页 |
| ·Studies in L2 Acquisition concerning the Asymmetry of Null Subjects and Null Objects | 第21-24页 |
| ·Studies at Home | 第24-25页 |
| ·Summary | 第25-26页 |
| 3 Theoretical Background | 第26-32页 |
| ·The Theory of UG | 第26页 |
| ·Access to Universal Grammar in Second Language Acquisition | 第26-27页 |
| ·Differences between English and Chinese | 第27-30页 |
| ·From the Perspective of Pro-drop Parameter | 第27-28页 |
| ·From the Perspective of Language Typology | 第28-30页 |
| ·Subject-prominent Languages Vs. Topic-prominent Languages | 第28-29页 |
| ·Expletive Subjects in English Vs. Null Arguments in Chinese | 第29-30页 |
| ·Summary | 第30-32页 |
| 4 Empirical Study | 第32-49页 |
| ·Hypotheses | 第32-33页 |
| ·Subjects | 第33页 |
| ·Tasks | 第33-34页 |
| ·Scoring | 第34-35页 |
| ·Results | 第35-48页 |
| ·Difference between Unlearning of Null Subjects and Unlearning of Null Objects | 第35-36页 |
| ·Difference among Unlearning of the Five Types | 第36-40页 |
| ·Difference among Three Groups of Learners | 第40-46页 |
| ·Effect of Topic Construction Transfer on Null Subjects | 第46-48页 |
| ·Summary | 第48-49页 |
| 5 Discussion | 第49-62页 |
| ·Explanation for the Asymmetry between Null Subjects and Null Objects | 第49-55页 |
| ·Explanation for the Performance Difference between Matrix Subjects and Embedded Subjects, between Matrix Objects and Embedded Objects | 第55-56页 |
| ·Explanation for the Performance Difference between Expletive Subjects and Referential Subjects | 第56-57页 |
| ·Analysis of Null Subject Sentences Related with Transfer of Chinese Topic Constructions and Explanation for Transfer of Chinese Topic Constructions in L2 English Acquisition | 第57-60页 |
| ·Analysis of Null Subject Sentences Related with Transfer of Chinese Topic Constructions | 第57-59页 |
| ·Explanation for Transfer of Chinese Topic Constructions in L2 English Acquisition | 第59-60页 |
| ·Summary | 第60-62页 |
| 6 Conclusion | 第62-64页 |
| ·Summary of the Study | 第62-63页 |
| ·Pedagogical Suggestions | 第63页 |
| ·Limitations of the Study and Suggestions for Future Research | 第63-64页 |
| References | 第64-68页 |
| Appendix A | 第68-70页 |
| Appendix B | 第70-72页 |
| Appendix C | 第72-74页 |
| Academic Achievements | 第74-75页 |
| Acknowledgements | 第75页 |
