In a series of production and grammaticality judgment experiments, I investigated the status of children's non-adult questions with 2 auxiliary verbs, such as "What did the smurf didn't buy." Previous studies showed that these questions were produced primarily in negative contexts. In the first part of the study, I tested whether children produce them in positive contexts with contrastive stress. The results confirm that these questions are limited to negative contexts. In the second part, I tested how children judge these questions. If children produce these questions because they have a non-adult grammar, then they should accept these questions. However, the results from 15 children (age 3;11-4;11) show that they produced these questions but judged them unacceptable. I argue that the production of these questions is not the result of a non-adult grammar but rather the result of a performance phenomenon based on incorrect lexical information regarding constituent negation.