This paper weighs the implications of Second Language Acquisition (SLA) research and practice for Speech and Language Technology in Education (SLaTE). It describes the different psychological processes of implicit learning, explicit learning, and explicit instruction, and reviews educational research into the benefits and limitations of each. It considers how SLA differs from first language acquisition and, therefore, why implicit learning from usage does not suffice for SLA. It outlines the range of types of knowledge necessary for fluent nativelike proficiency, and how this requires a balanced learning curriculum that provides opportunities for implicit learning from meaning-based usage and explicit attention to form in use contexts. It then considers what SLaTE might offer in each of these domains.