Chapter 1 The Impairment of Interlanguage Syntax 1
1.1 Debate on the Impairment of Interlanguage Syntax 1
1.2 Research Questions and Singnificance 4
Chapter 2 Previous Studies and Theories of Inflectional Optionality 8
2.1 Inflectional Optionality 8
2.2 Root Infinitives in L1 Grammars 10
2.3 Inflectional Optionality in L2 Grammars 19
2.4 Problems with the Previous Studies 34
2.5 Improvements in the Present Study 42
Chapter 3 The Theoretical Framework 44
3.1 The Grammar Model of the Minimalist Program 44
3.2 Cross-Linguistic Variation 45
3.3 Functional Categories 46
3.4 Features and Feature Checking Theory 48
3.5 Finiteness in English and Chinese 55
Chapter 4 The Empirical Study 75
4.1 Hypotheses 75
4.2 The Case Study 77
4.3 The Cross-Sectional Study 98
4.4 Acquisition of the Suppletive Be 126
4.5 Theoretical Accounts 140
Chapter 5 Causes of Missing Inflections in L2 159
5.1 Testing of the Previous Accounts 160
5.2 Other Factors Affecting Inflection Suppliance in L2 173
5.3 Morphological Competence 177
Chapter 6 Concluding Remarks 181
Appendix Ⅰ Test Used in the Cross-Sectional Study 187
Appendix Ⅱ Examples of the Overuse of the Suppletive Be The Case study 191
Appendix Ⅲ Verbs with Regular Inflection in the Case Study 201
Appendix Ⅳ Agreement Errors in the Cross-Sectional Study 206
References 208