摘要：Issues of learnability and teachability of linguistic features have long been a core interest in instructed second language acquisition (SLA) research. Following Lyster and Ranta (1998), a great deal of empirical work has approached second language (L2) teachability by investigating the efficacy of all types of corrective feedback (e.g., oral recasts, elicitation, repetition) vis-à-vis the acquisition of L2 English structures such as third-person singular -s, past tense ending -ed, and the use of first mention a/an. That said, the choice of these linguistic targets appears to be quite arbitrary. In other words, they were chosen because they were “thought” to be somewhat unlearnable, often without further explanation as to how the estimated level of learnability was determined. In this light, Han’s (2009) Selective Fossilization Hypothesis (SFH) seems promising in informing L2 teaching practices, as it approaches the learnability issue – generally believed to be the flipside of the phenomenon of fossilization – both a priori and a posteriori.
