Three experiments examined the conditions under which infants acquiring English succeed in mapping novel adjectives, applied ostensively to individual objects, to other objects with the same property (color or texture). Twenty-one-month-old infants were introduced to a target (e.g., a yellow object) and asked to choose between (1) a matching test object (e.g., a different yellow object) and (2) a contrasting test object (e.g., a green object). Infants hearing the target labeled with novel adjectives were more likely than those hearing no novel words to choose the matching test object. Infants also revealed an emerging distinction between novel adjectives and nouns. Finally, infants' expectation regarding the extension of adjectives appears to unfold within the support of a familiar basic-level category. Infants extended novel adjectives to the matching test object when all objects were all drawn from the same basic level category; they failed to do so when the objects were drawn from different basic level categories.