Explaining phenomena of first and second language acquisition with the constructs of implicit and explicit learning: The virtues and pitfalls of a two-system view

This chapter examines to what extent Krashen’s (1981) distinction between acquired (implicit) and learned (explicit) knowledge can be upheld from a usage-based view on first and second language learning and in the light of recent advancement in (neuro)cognitive research on artificial grammar learning, statistical learning, and modelling implicit and explicit learning. It is proposed that, generally, two-system theories (e.g. implicit/explicit, declarative/procedural) appear to account for first and second language acquisition. However, given the complexity of language systems, the complexity of the human brain, and the possibility that consciousness should be conceived of as a scale rather than as a dichotomy, it might well be that a two-system view is too simple. The paper ends with partly speculative answers to six fundamental questions concerning implicit and explicit first and second language acquisition and an agenda for their investigation.