The match/mismatch between language used in child books and actual language used as measured by Turkish cdi

Choosing the right book for the appropriate age level has great importance and effects on children?s development of vocabulary and grammar acquisition. In the child books, the language used above the vocabulary and grammar level of the child will surpass the benefits of reading books to children. For this reason, so as to choose a child book, being aware of the language of the child has great importance. The first aim of this study is to reveal if the vocabulary 8-30 month old children use as determined by Turkish CDI match with the vocabulary present in thirteen child books written for 0-3 years of age and chosen from four different publishers. Another aim of this study is to investigate if the grammatical forms that 16-30 month old toddlers use match with the grammatical forms that are present in the child books. In addition, this study also aims to explore if the grammatical forms that children are able to produce increase as their lexicon grows.After addressing the issues of terminology and definitions, related literature focused on the studies and theories on the comprehension and production of children, acquisition of lexicon and grammar and the contributions of reading books to children. It also focused on the history of the data collection tool of the present study: CDI. Turkish CDI is a parental report method therefore, Turkish adaptations of CDIs were handed out to the parents and they were asked to fill in the checklists that provide to follow the comprehensive and productive vocabulary and grammatical development of their children.The results show that vocabulary items such as sound effects, toys, body parts, small household items, furniture and rooms, people, verbs and postpositions are present both in the books chosen and child vocabulary as measured by Turkish CDI. However, in the child books, words in animals, vehicles, clothes, outside items, words about time, description words, pronouns, question words and quantifiers categories do not match with the words that are produced by children.In an overall evaluation, our results indicate that the grammatical items that are present in the child books do not match with the grammatical items that are produced by 16-30 month old toddlers. There are also additional grammatical items that are frequently produced by toddlers, but do not take place in the child books such as, suffixes for negation, causative, passive, unergative, reported past in simple past.Lastly, the relationship between the lexicon and grammar growth of 16-30 month old toddlers was investigated. The results show that as children get older and expand their vocabulary, the number of grammatical morphemes they use increases.Keywords: Comprehensive vocabulary, productive vocabulary, grammatical forms, child books, Turkish CDI.