Idealization plays a fundamental role in scientific inquiry. This article examines the case for maintaining the claim that the second language acquisition (SLA) of grammatical structures such as negation manifests identifiable stages of acquisition. It proposes that, while research has demonstrated the need for de-idealization, there is no need to…

This article examines the concept of simplification in second language (SL) learning, reviewing research on the simplified input that both naturalistic and classroom SL learners receive. Research indicates that simplified input, particularly if derived from naturally occurring interactions, does aid comprehension but has not been shown to…