A study compared mothers' and fathers' speech patterns when speaking to preschool children, particularly utterance length, sentence types, and word frequencies. All of the children attended a nursery school with a student population of 136 in a large urban area in the Southwest. Volunteer subjects, 28 mothers and 28 fathers of 28 children who ranged in age from two years eight months to three years five months, were video and audio taped as they played with their children in a playroom before having an individual conference with the child's teacher. Both the mother and the father were observed when alone with the child. Analysis of the tapes suggested that parents modify their language in similar ways in order to accommodate their preschool children, although their communication patterns appear to vary in the areas of sentence types and word frequencies. Fathers used significantly more interrogative sentences, while mothers used significantly more declarative sentences. More research is needed to clarify the ways in which parents modify their language for their children and to take into account the sex of the child, the educational level of the parents, and the socioeconomic differences among parents. (DF)