I-IV -- Preface -- Contents -- Acknowledgements -- List of figures -- List of tables -- 1. Answering systems -- 2. Welsh echo responsives -- 3. Welsh echo and nonecho responsives -- 4. Discourse functions of Welsh responsives -- 5. A formal analysis of Welsh responsives -- 6. Children's use of Welsh responsives -- 7. Language contact: the influence of English -- 8. Internal causes of variation -- Appendix I. Conventions in the corpus examples -- Appendix II. Conventions in the interlinear glosses -- Appendix III. Additional examples of responsives -- Appendix IV. Examples of formal answering systems -- Notes -- References -- Index -- Errata -- 362-366