Although there is considerable evidence that nouns highlight category-based commonalities, including both those that are perceptually available and those that reflect underlying conceptual similarity, some have claimed that words function merely as features of objects. Here, we directly test these alternative accounts. Four-year-olds (n = 140)…

A precisely controlled automated procedure confirms a developmental decalage: Infants acquiring English link count nouns to object categories well before they link adjectives to properties. Fourteen- and 18-month-olds (n = 48 at each age) extended novel words presented as count nouns based on category membership rather than shared properties. When…

Investigated whether infants can construe the same set of objects as an object category or as embodying an object property. Results of 2 experiments involving 48 and 64 14-month-olds respectively suggest that infants have begun to distinguish nouns from adjectives, they expect different grammatical forms to highlight different aspects, and that…