Semantic Constraints on Word Learning: Proper Names and Adjectives

4 experiments examined 3‐ and 4‐year‐olds' interpretations of novel words applied to familiar objects in the sentence frame, “This Y is X,” where X is a novel word, and Y is a familiar basic‐level count noun (e.g., “dog”, “cup”). These novel words are ambiguous and could be interpreted either as proper names (e.g., “Fred”) or as adjectives/mass nouns (e.g., “red”/“lead”). The experiments addressed 2 questions. First, do children appreciate that the words can be construed either as proper names referring to individuals or as adjectives/mass nouns referring to salient properties/material kinds? The results showed that children could easily make either interpretation. Second, what factors affect children's tendency to make either a proper name or an adjective/mass noun interpretation? In the experiments, children learned the novel words for a range of animals and artifacts. Most children who learned the words for typical pets (e.g., a bird) made proper name interpretations, as did the majority of those who learned the words for certain non‐pet animals (e.g., a caterpillar) described as possessed by someone, but only about half of those who learned the words for such non‐pet animals not so described. Very few children who learned the words for either simple (e.g., a shoe) or complex (e.g., a boat) artifacts made proper name interpretations. The results provide clear evidence of the role of semantic information in constraining children's interpretation of a novel word, and they help to refine an understanding of what counts as a nameable individual for preschoolers.