These studies address monolinguals' and bilinguals' processing of categories, in order to examine the relationship between concepts and linguistically encoded classes. We focus on languages that differ in their conceptual lexicalization and breadth of application, where one language has a single word (e.g., dedo in Spanish) that corresponds to two words in another language (e.g., English finger and toe). Categories differed across types of semantics-concept mappings, from ‘classical’ cases, involving members close in the conceptual space, to ‘homonyms’, involving conceptually distant items. Bilingual Catalan speakers, and English and Spanish monolinguals judged whether objects were ‘like’ an initial referent presented either with or without a label. Scores were highest in classical categories, lowest in homonyms; higher in narrow than wide categories; and better in labeled than unlabeled cases. Bilinguals outperformed monolinguals in judgments that conformed with their language, especially in wide categories. We discuss implications for the semantics-cognition interface and bilingualism.