The role of memory and language ability in children's production of two-clause sentences containing before and after.

We assessed 3- to 6-year-old children's production of two-clause sentences linked by before or after. In two experiments, children viewed an animated sequence of two actions and were asked to describe the order of events in specific target sentence structures. We manipulated whether the target sentence structure matched the chronological order of events (e.g., "He finished his homework, before he played in the garden" [chronological order]) or not (e.g., "Before he played in the garden, he finished his homework" [reverse order]). Children produced fewer accurate target sentences when the presentation order of the two clauses did not match the chronological order of events, specifically for target sentences linked by after. Independent measures of vocabulary and memory both were related to performance, but vocabulary was the stronger predictor. We conclude that developmental improvements in children's ability to produce two-clause sentences linked by a sequential temporal connective are driven primarily by language ability rather than memory capacity per se. This work also highlights the advantages of using both sentence repetition (Experiment 1) and blocked elicited production (Experiment 2) paradigms to elicit sentence production in young children.