Abstract The current study investigated the role of morpho-phonological and syntactic factors in judging the marking of Hebrew adjectives in agreement with plural nouns of differing categories of regularity. Participants were 36 literate adult speakers of Hebrew, who were administered a judgment test of 144 sentences (half grammatical and half ungrammatical), each containing a plural adjective in agreement with a nominal head. The task sentences were divided into three different syntactic configurations of the adjective in relation to the noun—predicative adjectives, attributive adjectives in sentence-initial NPs and attributive adjectives in sentence-final NPs. The agreement-assigning nouns were classified according to three morphological criteria: Noun gender (masculine and feminine), Noun suffix (regular, irregular, and ambiguous), and noun stem (changing and non-changing stems). Results showed that gender was the most important factor affecting agreement judgment: adjectives agreeing with ambiguous and opaque feminine nouns taking irregular suffixes yielded the lowest accuracy scores and the longest reaction times. Syntactic position affected judgment scores as well, with predicative and attributive-initial adjectives being more difficult to process than attributive-final adjectives. These results support the view that categories of number and gender emerge from the morpho-phonological properties of words learned in their syntactic and semantic contexts.