Hart and Risley's unparalleled study took 1,300 hours over 2 1/2 years and involved 42 diverse families with young children. One book to examine the date and its implications just wasn't enough. This second volume retells the story of reliability-tested data in a fascinating account of how childen's practice of speech as shaped by family interaction affects learning to talk. This book charts the month-by-month growth in children's vocabulary, utterances, and use of grammatical structures and describes the ambient conversation and changing patterns of parent-child interaction as the children's contribution to those exchanges increases. Supplementing this narrative are transcriptions from observed interactons and an extensive appendix listing more than 2,000 words of children's vocabulary from 11 to 36 months of age. Integrating childen's practice with the language experience provided by their parents, this much-awaited volume reveals the pattern of the "social dance" of children learning to talk with their families.