negative interrogative clauses

Here is another difficult point to understand in the EGP because it is so general and there are so many other points that are more specific.

A2 Point 11 in CLAUSES:

negative interrogative clauses.

The English Grammar Profile examples:


There is not much value in expanding this point for examples since they will mostly overlap or clash with other more specific points.  One might also ask why not just list this point in the category of questions.