Judging Hebrew adjective agreement across development: syntactic and morpho-syntactic awareness

Grammatical awareness of syntax and morphology is important in children’s literacy development for both reading and writing. Hebrew, a language with rich inflectional morphology, marks nouns for plural number in conjunction with gender. Hebrew attributive adjectives agree with noun number and gender in the same noun phrase, while predicative adjectives are in agreement with the grammatical subject in the same clause. Since adjectives are dependent on nouns, regularity or irregularity of plural marking on nouns directly affects plural agreement marking on adjectives. Given the importance of word order to Hebrew syntactic acquisition, the syntactic positions and functions of adjectives should also play a role in learning to inflect them. The current study examined Hebrew speakers’ developing ability to correctly identify adjective agreement with plural nouns given noun (ir)regularity and adjective syntactic position in children, adolescents, younger and older adults. Accuracy and reaction time were the measures used to trace this development. Findings showed that judgment increased in accuracy and decreased in RT, with feminine noun gender in conjunction with suffix irregularity challenging acquisition. Processing factors associated with the position and syntactic function of the adjective enhanced this difficulty sometimes even in adults. These results shed light on the psycholinguistic mechanisms used in syntactic and morphological judgment and on the ways they change with age and schooling.