Bilingual toddlers' comprehension of mixed sentences is asymmetrical across their two languages

This study tested Spanish-English bilingual toddlers’ processing of single-language and mixed-language sentences. Processing was disrupted when toddlers heard a heard a switch from their dominant to non-dominant language, but not vice versa, and they benefited from hearing nouns produced in their dominant language, independent of switching. These results suggest a united picture of early monolingual and bilingual learning: with experience, toddlers integrate knowledge of familiar regularities and representations of individual words to process language efficiently.