This paper considers language development among children and discusses the influence of the learning environment in the acquisition of language use as distinct from language structure. The results of the five studies reported here suggest that the child is aided by what he is encouraged to say, not simply by what he hears, and that adults seem to be essential for such encouragement. Language development proceeds most efficiently, both in functions as well as structure, when motivated by powerful communicative intent. The group instructional environment must be natural and less didactic; it should be possible to maximize familiarity in child-adult relationships and guarantee that the children who need talking time with adults get it. A bibliography is provided.(VM)