Asymmetrical Knowledge of Ungrammaticality in SLA Theory

The present paper addresses the argument that access to UG in SLA implies an asymmetrical knowledge of ungrammaticality, which is evidenced in superior accuracy and uniformity in learners' judgments of ungrammatical structures versus grammatical structures (Felix, 1988; Zobl, 1992). I attempt to show that the asymmetry position is conceptually defective, that the evidence for it is inconclusive and inappropriate, and that the evidence adduced is contradicted by other data.