I frequently see contractions such as "isn't" and "wasn't" used in sentences such as:
Why wasn't she there?
Which would be equivalent to:
Why was not she there?
Which doesn't make any sense. Considering how often I see this used I thought I could find something online about it, however I haven't had any luck.
Is it grammatically correct to use "isn't" and "wasn't" in sentences like the one above, and the one below? If so, why?
Why isn't Dad home yet?