child will hear sentences which are badly formed due to performance errors, e.g. the speaker
losing track of singular-vs.-plural in the course of a longish sentence. We take it for granted that
these are not properly formed sentences, but a child without innate syntactic ideas should not be
expected to know this.
The child with an empiricist psychology would also be misled by sentential
transformations appearing to point to one sort of rule, when in fact the actual linguistic rule is
quite different. Consider an illustration involving movement, the transformation of one sentence
into another by reordering elements. Let’s suppose that Locke was right about the mind; the
infant’s mind is like white paper upon which experience impresses all the concepts which it ever
shall acquire. Now let us imagine how this white-paper child, growing up in an Anglophone
community, would learn about movement. Suppose that the child hears the following utterances
on various occasions:
“The book is on the table.”
“Is the book on the table?”
“The red book is on the table.”
It would be natural for the white-paper child to conclude that the following is a well-formed
sentence, even though we know that it is not:
“Book the red is on the table?”
The white-paper child would reach this conclusion because it hypothesizes (2) the rule that
moving the third word to the beginning forms a question. Judging from the first two sentences