The seeming absence of negative evidence in the input that children receive during language acquisition has long been regarded as a serious problem for non-nativist linguistic theories. Among the solutions that have been suggested for this problem, preemption by competing structures is doubtless the most intensively researched and widely accepted. However, while preemption works well in the domain of morphology, it cannot apply categorically in the domain of syntax, as this would preclude the existence of semantically overlapping constructions, such as (...) the ditransitive and the prepositional dative, which can be used alternatively with many, but not all, verbs of literal or metaphorical transfer. This paper investigates one specific version of preemption briefly entertained by Pinker (Language learnability and language development, Harvard University Pressm, 1984), which would account both for the existence of semantically overlapping constructions and for the fact that these constructions may preempt each other in the case of individual verbs. Typically, such pairs of grammatical constructions differ in their information-structural restrictions and speakers tend to choose the construction that best fits a given discourse context; when speakers use a construction even though there is an alternative that fits the discourse context better, children may take this as evidence that the alternative is not available for the specific verb in question. Two corpus studies are presented, comparing the information-structural profile of prepositional dative constructions containing verbs that may alternate between the dative and the ditransitive with the information structural profile of verbs that are restricted to the prepositional dative. For Pinker's preemptive mechanism to be feasible, there should be a clear and systematic difference in the information-structural profile of these two classes of verbs. However, no such difference can be found in actual usage. (shrink)