A discussion of research in the area of retardation influenced by recent developments in psycholinguistics, the problem of language assessment, and the problem of language training, first considers a review by D.R. Olson on language, the concept of transformational grammar, syntactic structure of sentences, the acquisition of linguistic meaning, and the interaction between innate biological factors and environmental influences. Studies on the language of the retarded are cited which indicate a connection between motor or chronological development and language development and which imply that language development in the retarded is slower rather than qualitatively different from that of normal children. Criticism is directed toward the Illinois Test of Psycholinguistic Abilities and the Peabody Language Development Kit on the grounds that neither is based on a viable model of linguistic competence and performance and that neither reflect recent work in the area of developmental psycholinguistics. Minimal requirements for a language assessment device are outlined in transformational terms as are hypotheses for research in language training. (RP)