| Acknowledgements | 第1-6页 |
| Chinese Abstract | 第6-7页 |
| English Abstract | 第7-10页 |
| Chapter 1 Introduction | 第10-15页 |
| ·Background of the Study | 第10-12页 |
| ·Significance of the Study | 第12-13页 |
| ·Framework of the Study | 第13-15页 |
| Chapter 2 Literature Review | 第15-34页 |
| ·The Critical Period Hypothesis | 第15-20页 |
| ·The Critical Period in First Language Acquisition | 第16-17页 |
| ·The Critical Period in Second Language Acquisition | 第17-19页 |
| ·The Sensitive Period Hypothesis | 第19-20页 |
| ·Studies at Home and Abroad | 第20-26页 |
| ·Studies Abroad | 第20-24页 |
| ·Studies at Home | 第24-26页 |
| ·Characteristics of Learners of Different Ages | 第26-28页 |
| ·Explanations for the Age Learning Differences | 第28-34页 |
| ·Neurological Difference | 第28-29页 |
| ·Social-psychological Difference | 第29-30页 |
| ·Input Difference | 第30页 |
| ·Cognitive Difference | 第30-31页 |
| ·Affective Difference | 第31-34页 |
| Chapter 3 The Current Study | 第34-41页 |
| ·Research Questions | 第34页 |
| ·Subjects | 第34-35页 |
| ·Instruments | 第35页 |
| ·Procedures and Methods | 第35-38页 |
| ·Procedure and Method of Grouping the Subjects | 第35-36页 |
| ·Procedure and Method of the Data Collection | 第36页 |
| ·Procedure and Method of the Tape Recording | 第36-38页 |
| ·Data Analysis | 第38-41页 |
| Chapter 4 Conclusion and implications | 第41-46页 |
| ·Findings | 第41-42页 |
| ·Conclusion | 第42-43页 |
| ·Limitations | 第43页 |
| ·Further Research Question | 第43-44页 |
| ·Implications for an Optimal Starting Age | 第44-46页 |
| Chapter 5 Suggestions for Future Language Teaching | 第46-52页 |
| ·Suggestions for the Teaching of Children | 第47-49页 |
| ·Suggestions for the Teaching of Adolescents | 第49-50页 |
| ·Suggestions for the Teaching of Adults | 第50-52页 |
| References | 第52-56页 |
| Appendix | 第56-57页 |
