Intersections between key questions in second language acquisition and neurolinguistic research findings.

This article reviews three central questions in second language acquisition (SLA) research: the role and nature of input, explicit versus implicit knowledge, and formal language instruction in second language development. It emphasizes that meaningful, comprehensible input is essential for language acquisition, with learners developing an implicit mental system distinct from explicit, conscious knowledge; these two knowledge types are qualitatively different and not directly connected. Formal language instruction has a limited but potentially facilitative role, primarily by helping learners process input more effectively rather than altering developmental stages or internal mechanisms. The article also highlights intersections with neurolinguistic research, which supports the primacy of implicit, immersion-like input over explicit instruction for proceduralizing grammar and achieving native-like processing. Finally, it outlines pedagogical implications favoring input-oriented, meaning-based teaching and calls for further research using online measures to better understand how instruction affects implicit language processing.