  Chomskyans respond in two main ways to findings like this. First,  they argue, it is not enough to show that some children can  be expected to hear sentences like Is the girl in the jumping  castle Kayley's daughter? All children learn the  correct rule, so the claim must be that all children are  guaranteed to hear sentences of this form — and this claim is  still implausible, data like those just discussed   notwithstanding.[8]  In order to take this question further, it would be necessary to  determine when in fact children master the relevant structures, and  vanishingly little work has been done on this topic. Sampson  2002:82ff. found no well-formed auxiliary fronted questions (like  Is the girl who is in the jumping castle Kayley's daughter?) in his sample of the British National Corpus. He notes that in  addition to supporting Chomsky's claims about the poverty of the  pld, such data simultaneously problematize his claims about  children's knowledge of the auxiliary-fronting rule itself. Sampson  found that speakers invariably made errors when apparently attempting to produce complex auxiliary-fronted questions, and often emended  their utterance to a tag form instead (e.g., The girl who's in  the jumping castle is Kayley's daughter, isn't she?).  Hespeculates that the construction is not idiomatic even in adult  language, and that speakers learn to form and decode such questions  much later in life, after encountering them in written English. If  that were the case, then the lack of complex auxiliary fronted  questions in the pld would be both unsurprising and  unproblematic: young children don't hear the sentences, but nor do  they learn the rule. To my knowledge, children's competence with the  auxiliary fronting rule has not been addressed   empirically.[9] 