This paper summarizes the findings of three studies used to develop a language assessment instrument and to explore the relationships between language, cognitive development, and reading achievement in poor children. A sentence repetition task provided scores for function word omission, function word correct and reconstruction word correct. These scores were found to be correlated with reading ability and problems. The sentence repetition task also identifies four distinctly different groups: children who are delayed in language development and who use either standard or non-standard vernacular, and children who are at a normal level of language development who use either standard or non-standard vernacular. The procedure and task can be used by the classroom teacher in assessing language development in kindergarten through third grade. Findings are discussed in terms of the cognitive deficit-culturally different controversy. (ED)