Vocabulary Size and Depth of Word Knowledge in Adult-Onset Second Language Acquisition
This study investigated whether adult-onset second language (L2) learners achieve native level vocabulary after decades of immersion. Vocabulary tests were given to three groups of participants: highly successful adult-onset learners of English, monolingual English speakers, and bilingual native speakers of English. Overall, the native speakers outperformed the non-native speakers; however, the rate of native like achievement was remarkably high among the successful adult-onset learners, which indicated that native level L2 vocabulary size and depth of word knowledge were attainable in adulthood. Factors that correlated with native level L2 vocabulary were: childhood caregivers' education, verbal ability and literacy in the native language, and interest in word learning and daily reading. The findings suggest that the lexicon may be the potentially most successful area of adult-onset L2 learning.
Hellman, Andrea B. "Vocabulary size and depth of word knowledge in adult‐onset second language acquisition." International Journal of Applied Linguistics 21, no. 2 (2011): 162-182.
International Journal of Applied Linguistics