A descriptive, developmental study of children's imitation of interrogative sentences was conducted among 16 preschool and 15 kindergarten children acquiring English as either a native or a second language. A program of language activities based on four American folk rhymes (three in the form of a rhythmic dialogue and the fourth an antiphonal chant) was introduced into the children's classrooms. The program was implemented once a week for approximately 15 weeks at both grade levels. The folk rhymes were used by the teacher/observer in conjunction with verbal and nonverbal, motoric interaction activities in structured groups and semi-structured teacher-child interactions. Children's imitations of the folk materials were tape recorded and transcribed. Anecdotal reports of spontaneous peer interactions and private uses of the folk materials were also part of the research design. Among the results, imitations of interrogative patterns were found to be filtered through the children's rule systems. Four types of developmental error were identified. The four children learning English as a second language, who provided the most complete data records, were found to move through predicted stages of developmental error. It is concluded that imitative activities conducted in a Piagetian context of active accommodative behavior appear to be valid for an early childhood language program. (Author/RH)