Rules and instances in foreign language learning: Interactions of explicit and implicit knowledge

Abstract This paper reports a study of implicit and explicit learning of second language (L2) grammatical forms, the “soft”-mutations of Welsh. “Random” learners saw randomly ordered instances. “Rule” learners first learned the rules. “Rule&Instances” learners saw the rules applied to instances. Initial learning, generalisations to new words and constructions, implicit fast performance in a well-formedness RT decision task, and explicit knowledge of the rules were recorded. Analyses of over 71,000 language trials demonstrate: (1) “Random” learners quickly achieve competence on original learning material, but show little implicit learning, performing poorly on well-formedness (or “grammaticality”) judgements, and have poor acquisition of explicit knowledge of the underlying rule-structure. (2) “Rule” learners take many trials to learn the rules but this facilitates their understanding of the natural language. However, they often know rules explicitly, yet fail to apply them in practice. Explicit and implicit knowledge are doubly dissociated. (3) Initially, “Rule&Instances” learners learn slowest. However, they alone abstract a working knowledge of soft-mutations. When exposed to new constructions, they generalise and are able both to explicitly formulate the new rules and succeed on implicit well-formedness judgements.