Children ranging in age from 1;1 to 1;3 were presented with 16 contrived lexical concepts, each consisting of a nonsense word (eight object words and eight action words) and four unfamiliar exemplars that served as the referents for that word. Overall, the children used 65% of the experimental words one or more times to refer to at least one of their respective exemplars. Children acquired a greater number of object words than action words. In addition, words that were consistent with the children's initial phonologies were acquired in greater numbers. With respect to these results, speed of acquisition paralleled number of words acquired. Data revealed no significant differences in the role played by functional vs. perceptual similarity between objects or actions. There appeared to be no relationship between performance of actions and later acquisition of object words; however, children acquired few action words for actions they did not perform. (JB)