Input variability is key in many aspects of linguistic learning, yet variability increases input complexity, which may cause difficulty in some learning contexts. The current work investigates this trade-off by comparing speaker variability effects on L2 vocabulary learning in different age groups. Existing literature suggests that speaker…

The fundamental difference hypothesis (FDH), as formulated by Bley-Vroman (1990), claims that SLA tends to be nonconvergent because domain-specific linguistic mechanisms available in early childhood cannot be used for language learning in adulthood: Instead, second language (L2) learners deploy domain-general problem solving skills. I claim that…

Presents data on the past and present state of research on the interlanguage hypothesis, with specific attention to its extension to children. Outlines a dual approach to developing a theory of second language acquisition--a macrobehavioral approach and a neurofunctional approach. Finally, problems for the interlanguage hypothesis are discussed.…