The development of language has received considerable attention in recent years from speech pathologists, psychologists and educators. Much has been written on the nature and development of the elements and structure of language in normal children, but less attention has been given to the development of vocabulary and syntax in mentally retarded individuals. This study was designed to determine the relationships of language development (vocabulary and syntax) and age (chronological and mental). Twenty-nine mentally retarded children between the ages of three and eight were selected for study. Selection was based on scores from intelligence tests. The Peabody Picture Vocabulary Test (Dunn, 1959) and the Northwestern Syntax Screening Test (Lee, 1969) were administered to these children in order to derive receptive vocabulary, receptive syntax and expressive syntax scores. Observed and derived scores from normative data were recorded. Comparisons within each test were made by statistical analyses in order to determine significant differences between the rate of vocabulary and syntax development in normal and mentally retarded children
