Preface -- TABLE OF CONTENTS -- List of Tables -- 1. The Problem and the Data -- 2. Single-Word Utterances and Grammar -- 2.1. Explaining the Transition to Syntax -- 2.2. Conceptual Relations in Early Sentences -- 2.3. The Origin of Sentences and Linguistic Theory -- 3. Single-Word Utterances Are Not Sentences -- 3.1. /wídɘ̀/ : The Archetypal Pivot -- 3.2. Successive Single-Word Utterances -- 3.3. Comprehension and Syntax -- 3.4. Early Prosody and Syntax -- 4. Developmental Change in the Use of Single-Word Utterances -- 4.1. The Distinction Between Classes of Single Words -- 4.2. The Development of Substantive Words -- 4.3. The Use of Function Forms as Single-Word Utterances -- 4.4. The Use of Substantive Forms as Single-Word Utterances -- 5. Concepts, Words, and Sentences -- 5.1. Conceptual Notions Underlying Single-Word Utterances and the Origin of Grammar -- 5.2. 'Rich' Interpretation of Syntactic and Single-Word Child Utterances -- References -- Appendix -- 1. Methods and Materials for Video Tape Recording -- 2. Video Tape Transcriptions -- I: 16 months, 3 weeks -- II: 19 months, 2 weeks -- III: 20 months, 3 weeks -- IV: 22 months -- Subject Index -- Name Index.