The paper examines a developmental approach to language acquisition in young disabled children. Issues of form, content, and function are explored, with function of communication seen as central for disabled children. The role of teachers and parents in requiring more sophisiticated language is considered. Questions of competence on either the infant's or the mother's part are raised along with factors affecting the environment. The authors stress the importance for most disabled language learners of providing the most normal environment possible. They further suggest that the forms expected of a child should be age- and environment-appropriate. The epigenetic principle is said to indicate the value of normal development for instruction, and mothers should follow the lead of younger and/or less competent children to ensure meaningful communication. (CL)