RED BLUEBIRDS AND BLACK GREENFLIES - PRESCHOOLERS UNDERSTANDING OF THE SEMANTICS OF ADJECTIVES AND COUNT NOUNS

Three experiments explored preschoolers' and adults' understanding of the distinctive semantic functions of adjectives (i.e., to name proper ties) and count nouns (i.e., to name object kinds). In Experiment 1, w e modeled a familiar adjective (e.g., ''blue'') syntactically as eithe r an adjective (e.g., ''This is a blue one'') or a count noun (e.g., ' 'This is a blue'') and applied it to a target object (e.g., a blue cre ature). In Experiments 2 and 3, we marked the adjective phonologically as either an adjective (e.g., ''This is a blue bird'') or a part of a count noun (e.g., ''This is a bluebird'') and applied it to a target object (e.g., a blue bluebird). In all experiments, participants then had to extend the expression they heard to either an object of a diffe rent kind with the same property as the target (e.g., a different crea ture or bird colored blue) or an object of the same kind with a differ ent properly (e.g., the same creature or bird colored red). Four-year- olds and adults, but not 3-year-olds, who heard the adjective version were more likely than those who heard the count noun version to choose the object with the same property. Thus, by the age of four years, ch ildren treated a word's lexical category, cued a syntactically or phon ologically, as a powerful cue to its meaning. (C) 1997 Academic Press.