| Acknowledgements | 第1-8页 |
| Abstract | 第8-11页 |
| 内容摘要 | 第11-13页 |
| Chapter One Introduction | 第13-18页 |
| ·Background of the Study | 第13-14页 |
| ·Methodology of the Study | 第14-16页 |
| ·Data Collection | 第16页 |
| ·The Layout of the Thesis | 第16-18页 |
| Chapter Two Previous Studies on the PCC | 第18-24页 |
| ·General Remarks of the PCC | 第18页 |
| ·Synchronic Studies on the PCC | 第18-21页 |
| ·Traditional Grammarians'Analysis of the PCC | 第18-19页 |
| ·Quirk et al's Classification of Conditional Sentences | 第19-21页 |
| ·Diachronic studies on the PCC | 第21-23页 |
| ·Deficiencies in Previous Studies on the PCC | 第23-24页 |
| Chapter Three Theoretical Preliminaries | 第24-35页 |
| ·Origin of Historical Pragmatics | 第24-25页 |
| ·Pragmaphilology and Diachronic Pragmatics | 第25-28页 |
| ·General Review of Grammaticalization | 第28-29页 |
| ·Grammaticalization in Historical Pragmatics | 第29-33页 |
| ·Theoretical Framework of the Project | 第33-35页 |
| Chapter Four Diachronic Form-to-Function Mapping on the PCC | 第35-54页 |
| ·Diachronic Study on the PCC | 第35-40页 |
| ·Providing | 第35-37页 |
| ·Provided | 第37-39页 |
| ·Supposing | 第39-40页 |
| ·Given | 第40页 |
| ·Types of the Change | 第40-49页 |
| ·Morphosyntactic Change of the PCC | 第41-43页 |
| ·Pragmatic-semantic Change of the PCC | 第43-46页 |
| ·Unidirectionality in the PCC Change | 第46-49页 |
| ·Motives of the PCC Change | 第49-54页 |
| ·Language Acquisition and Strategic Interaction | 第49-50页 |
| ·Repetition in Language Change | 第50-51页 |
| ·The Motivation of Pragmatic Inference of Language Change | 第51-53页 |
| ·Summary | 第53-54页 |
| Chapter Five Diachronic Function-to-Form Mapping on the PCC | 第54-59页 |
| ·The PCC Function as If in Conditional Sentences | 第54-55页 |
| ·Classification of Conditional Sentences with the PCC | 第55-57页 |
| ·Content-based Conditionals with the PCC | 第55-56页 |
| ·Epistemic Conditionals | 第56页 |
| ·Speech-act Conditionals | 第56-57页 |
| ·The Present Use of the PCC and If | 第57-59页 |
| Chapter Six Conclusion | 第59-62页 |
| ·Major Findings of the Study | 第59-60页 |
| ·Significance of the Study | 第60页 |
| ·Limitations and Suggestions for Further Research | 第60-62页 |
| References | 第62-68页 |
