This study examines the interaction between regularity and complexity in the acquisition of morphology and morpho-syntax in Hebrew nominal inflection. Seventy-eight Hebrew-speaking children, ages 4-8, were tested, using sentence completion tasks, on nine structures from three linguistic systems: singular adjectival agreement, noun pluralization, and plural adjectival agreement. Regularity and complexity emerged as organizing factors across ages: regular structures precede irregular ones, and within each level of regularity, less complex structures were acquired before more complex ones. The findings are discussed within the Dual-Route Model pointing to the difference between rule-governed and memory-based knowledge, while suggesting that the advantage of regularity could be attributed to frequency as well as to the strength of regularity cues in language acquisition, as proposed by Usage-Based models. The advantage of less complex structures over more complex ones is accounted for by the greater cognitive and linguistic effort required to acquire the latter.
Reznick et al. (Mon,) studied this question.