We evaluated external and internal sources of variation in second language (L2) and native language (L1) proficiency among college students. One hundred and twelve native-English L2 learners completed measures of L1 and L2 speaking proficiency, working memory, and cognitive control and provided self-ratings of language exposure and use. When…

Within the field of SLA, the incidence of nativelikeness in second language (L2) speakers has typically been explained as a function of age of acquisition. An alternative interpretation, however, is that L2 learners do not attain nativelike proficiency because of first language (L1) maintenance. This interpretation has nevertheless remained mostly…