A discussion of environmental variables in children's language development focuses on the impact on the child of his/her surroundings, and especially the adults (parents and other caregivers) with whom the child interacts. The paper reviews the related literature with attention to the following: the parents' responsibility for child language development; inborn traits of infants, especially sociability, that affect communication and language acquisition; the role of non-linguistic experience in concept formation; baby talk and "motherese" as tools for early communication; methods for promotion of adult-child communication; encouragement of imagination; the functions of imitation; variables in the home environment; the home-to-school transition; the school environment; and teachers' role in promoting communication. The importance of an adequate environment, and particularly of parental participation, in children's language development is stressed. (MSE)