Two retarded children were exposed to daily imitation training in which teacher or nurse modelled and instructed each child to imitate 12 sentences containing one of six animal names. The subjects were praised for correct verbal imitation. Across three phases of a multiple-baseline design, sentences varied as to the presence or absence of size and/or color adjectives describing the animals. In probe sessions at another time of day and in a different setting, the experimenter twice asked each subject to dfescribe 12 different animal pictures. The subjects' use of descriptive adjectives (color and/or size) greatly increased during probe sessions as a function of the sentence content (presence or absence of color and/or size adjectives) in modelling and imitation training sessions. Generalization to descriptions of animals also not used in imitation training sentences was also obtained..