This study investigated the linguistic characteristics of speech addressed to the child and the features of the verbal environment critical for learning language. The study focused on the prosodic and paralinguistic features of adult speech to the young child. Adult speech directed to children was compared to other kinds of systematic speech adjustments adults make in response to differing social situations. Speech samples of 24 mothers addressing their children were analyzed. The mean age of one half of the group of 24 children was two years, three months; the mean age of the other half was five years, four months. The adult speaker made a systematic adjustment in the prosodic and paralinguistic aspects of speech addressed to the young child, and these adjustments varied in relation to the age of the child listener. It is suggested that various features of the baby talk register can serve at least two functions, analytic and social. (Author/SW)