The effect of second-language experience on native-language processing

Previous work on bilingual language processing indicates that native-language skills can influence second-language acquisition. The goal of the present work was to examine the influence of second-language experiences on native-language vocabulary and reading skills in two groups of bilingual speakers. English-Spanish and English-Mandarin bilingual adults were tested on vocabulary knowledge and reading fluency in English, their native language. Participants also provided detailed information regarding their history of second-language acquisition, including age of L2 acquisition, degree of L2 exposure, L2 proficiency, and preference of L2 use. Comparisons across the two bilingual groups revealed that both groups performed similarly on native-language vocabulary and reading measures. However, in English-Spanish bilinguals, higher self-reported reading skills in Spanish were associated with higher English reading-fluency scores, while in English-Mandarin bilinguals, higher self-reported reading skills in Mandarin were associated with lower English reading-fluency scores. These findings suggest that second-language experiences influence native-language performance, and can facilitate or reduce it depending on the properties of the second-language writing system.