To examine whether children's acquisition of perspective-marking language supports development in their ability to reason about mental states, we conducted a longitudinal study testing whether proficiency with complement clauses around age 3 explained variance in false-belief reasoning 6 months later. Forty-five English-speaking 2- and 3-year-olds…

Replicates earlier studies and shows that children's ability to process syntactically well-formed sentences increases over the early school years. (Author/ED)

Elementary school children were exposed to a series of modeled, tape-recorded sentences; those containing nongrammatical prepositional constructions were always vicariously rewarded, while the remaining, grammatically correct, background sentences were not. (Editor)