Frontmatter -- Acknowledgements -- Contents -- Abbreviations and Symbols -- 1. Introduction -- 2. Informal outline -- 3. Data and previous accounts -- 4. Theoretical framework -- 5. The full account -- 6. Concluding remarks -- Appendix 1: Comparison to other languages -- Appendix 2: Chart of vocalic changes -- Appendix 3: Materials used for recordings -- References -- Index