On the learnability of implicit arguments

It has been argued that the experiencer argument of seem is always syntactically projected, and should thus induce an intervention effect even when not overtly produced. The results of our experimental study provide evidence for this claim - English-speaking children perform poorly on raising with seem, whether the intervening experiencer argument is overt or implicit. Conversely, Spanish-speaking children show adult-like performance with the raising semi-modal verb parecer `seem', which does not take an experiencer argument. This outcome raises questions regarding learnability, i.e. English-speaking children must know to project an implicit experiencer with seem, while Spanish-speaking children must not do so with the functional verb parecer. In this paper we provide a learning path that resolves this learning challenge.