Bencini, G. M. L. & Valian, V., (2008). Abstract sentence representation in 3-year-olds: Evidence from comprehension and production. Journal of Memory and Language. 59, 97-113.

Abstract:¬†We use syntactic priming to test the abstractness of the sentence representations of young 3-year-olds (35-42 10 months). In describing pictures with inanimate participants, 18 children primed with passives produced more passives (11 with a strict scoring scheme, 16 with lax scoring) than did 18 children primed with actives (2 on either scheme) or 12 children who received no priming (0). Priming was comparable to that reported for older children and adults. Comprehension of reversible passives with animate participants before and after priming was above chance but did not improve as a result of priming. Young 3-year-olds represent sentences abstractly, to have syntactic representations for noun, verb, “surface subject”, and “surface object”, to have semantic representations for “agent” and “patient”, and to flexibly map the relation between syntax and semantics. Taken together with research on syntactic categories in 2-year-olds, our results provide empirical support for continuity in language acquisition.