It is simply not possible that the child is acquiring the language principally through a
process of imitating adult speech. Certainly, children can be heard to repeat versions of
what adults say on occasion and they are clearly in the process of adopting a lot of vocabulary from the speech they hear. However, adults simply do not produce many of the expressions that turn up in children’s speech. Notice how, in the following extract (from Clark, 1993), the child creates a totally new verb (to Woodstock) in the context.