Children's comprehension of ‘because’ in reversible and non-reversible sentences

Comprehension of event order was compared for reversible ‘X because Y’ (‘Y because X’ is also logical) and non-reversible ‘X because Y’ sentences. Children aged 5; 8–10; 11 chose one of two picture sequences, differing in event order, and put two pictures in first/last order to match a sentence ‘X because Y’ (order of mention violates temporal order) or ‘Because Y, X’ (order of mention preserves temporal order). Reversibility and clause order effects reflected the use of semantic probability cues and order-of-mention strategies for comprehension. Judgements were also made of grammatical acceptability for correct and reversed ‘X because Y’ sentences. Response strategies used in the two experiments suggest that development of comprehension of the role of because reflects acquired independence from contextual support and acquisition of a meaning component: ORDER.