This study investigates three-to five-year-old children's interpretation of disjunction in sentences like "The dog reached the finish line before the turtle or the bunny". English disjunction has a conjunctive interpretation in such sentences ("The dog reached the finish line before the turtle and before the bunny"). This interpretation conforms with classical logic. Mandarin disjunction ("huozhe") can take scope over "before" ("zai..zhiqian"), so the same sentence can mean "The dog reached the finish line before the turtle or before the bunny (I don't know which)". If children are guided by adult input in the acquisition of sentence meanings, English-and Mandarin-speaking children should assign different interpretations to such sentences. If children are guided by logical principles, then children acquiring either language should initially assign the conjunctive interpretation of disjunction. A truth-value judgment task was used to test this prediction and English-and Mandarin-speaking children were found to behave similarly.