The speech of each of eight children aged 15 to 24 months was monitored in an informal setting and analyzed for the imitation of nonsense words introduced by the experimenter. In a second session, objects were introduced as referents for the nonsense words. Results failed to support the two initial hypotheses, namely that children imitate in part because the adult model contains phonological characteristics not yet incorporated in the infant's phonological system; and that a child's imitative utterances reflect phonological characteristics that overestimate the developmental level of the phonological system. The findings indicate that caution should be used in inferring selection patterns from data including imitative utterances, since selection constraints may relax in spontaneous speech and seem absent in imitation. The apparent relaxation of constraints may be facilitated by the demands of co-occurring developments in the child's lexical and semantic-syntactic acquisition. Children's imitations do not betray the phonological principles of the selection constraints still operating on their spontaneous speech in that they do not include consonants and syllabic shapes absent from the children's spontaneous usage. Exceptions to phonological patterns appear in imitative as well as spontaneous speech. (Author/JB)