The early use of person perception terms was examined via an analysis of the spontaneous speech of four young children in conversation with their parents at home. All four children were producing such terms early in their third year. Like their parents, children used the terms in two distinguishable ways: to attribute a trait to a person or to characterize a person's ongoing action. Most of these terms were evaluative, whether positive or negative. Parents often made direct comments to their children about both their traits and ongoing actions; children made similar comments about themselves. Parents also used person perception terms to make comments about others who were not party to the conversation; children did likewise. A considerable proportion of the trait terms that children produced served as interpretive comments on someone's actions or preferences. Our findings suggest that from an early age, children are trait theorists. Not only do they describe ongoing actions using trait vocabulary, they interpret those ongoing actions by attributing traits.