| 摘要 | 第1-6页 |
| Abstract | 第6-10页 |
| 1 Introduction | 第10-13页 |
| ·Background situation | 第10-11页 |
| ·Significance of the research | 第11-12页 |
| ·Layout of the dissertation | 第12-13页 |
| 2 Literature Review | 第13-34页 |
| ·A general reviews on age factors affecting SLA | 第13-14页 |
| ·The Critical Period Hypothesis in first language acquisition | 第14-20页 |
| ·Supports in favor of Critical Period Hypotheses in first language acquisition | 第15-19页 |
| ·The case of Victor | 第16页 |
| ·The case of Genie | 第16-17页 |
| ·The case of Chelsea | 第17-18页 |
| ·The case of Isabelle | 第18页 |
| ·The study on American Sign Language | 第18-19页 |
| ·Criticism for Critical Period Hypothesis in first language acquisition | 第19-20页 |
| ·Behaviorist point of view of critical period in first language acquisition | 第19页 |
| ·Piaget’s point of view | 第19页 |
| ·Problems with the three case studies | 第19-20页 |
| ·The Critical Period Hypothesis in second language acquisition | 第20-32页 |
| ·Evidence for the Critical Period Hypothesis in second language acquisition | 第21-26页 |
| ·Patkowski’s study | 第22-23页 |
| ·Johnson and Newport’s study | 第23-24页 |
| ·Long’s conclusions | 第24-25页 |
| ·Jia’s study | 第25页 |
| ·Studies by other researchers | 第25-26页 |
| ·Evidence against the Critical Period Hypothesis in L2 | 第26-31页 |
| ·Snow and Hoefnagel-Hohle’s study | 第26-28页 |
| ·Walberg and Rasher’s study | 第28页 |
| ·Johnstone’s study | 第28-29页 |
| ·Studies by other researchers | 第29-31页 |
| ·A reason for disagreement on the Critical Period Hypothesis | 第31-32页 |
| ·The sensitive period | 第32-34页 |
| 3 Research Design | 第34-42页 |
| ·Research purposes | 第34-35页 |
| ·Research questions | 第35页 |
| ·Participants | 第35页 |
| ·Data collection | 第35-39页 |
| ·Data from the Questionnaire | 第37页 |
| ·Data from the test of English morphology | 第37-38页 |
| ·Data from the test of English syntax | 第38页 |
| ·Data from the test of reading comprehension | 第38-39页 |
| ·Data analysis | 第39-42页 |
| ·Data analysis of Test of English Morphology | 第39页 |
| ·Data analysis of Test of English Syntax | 第39-40页 |
| ·Data analysis of Test of Reading Comprehension | 第40-41页 |
| ·Overall comparison of the mean scores of the three tests | 第41-42页 |
| 4 Findings and Discussion | 第42-49页 |
| ·Findings | 第42页 |
| ·Discussion | 第42-49页 |
| ·Respective advantages and disadvantages of learners of different ages | 第43-44页 |
| ·Advantages of very early starters | 第44-45页 |
| ·Advantages of early starters | 第45-46页 |
| ·The right time for children to receive bilingual education | 第46-49页 |
| 5 Conclusion | 第49-51页 |
| ·Conclusion | 第49-50页 |
| ·Limitations of the research | 第50页 |
| ·Further research questions | 第50-51页 |
| References | 第51-55页 |
| Appendix A | 第55-56页 |
| Appendix B | 第56-57页 |
| Appendix C | 第57-60页 |
| Appendix D | 第60-65页 |
| Acknowledgements | 第65-66页 |
