Published online by Cambridge University Press: 04 February 2010
Much second language acquisition (SLA) research confuses the representational and the developmental problems of language acquisition, assuming that attributes of a property theory will explain the transitions between the stages of a psychogrammar, or that induction will explain the properties of the representational systems which encode language. I argue that Principles and Parameter-setting theory deals only with the representational problem, and that induction must play a role in explaining the developmental problem. The conclusion is that both Epstein et al. and the papers they criticize are right; they are just not right about the same issues.