Negative if sentences are a bit more difficult. The "not" must be placed somewhere. "Will
" becomes "will not
" or "won't
" for short. This is still relatively easy. But if the if part is negative, you have to think about how to put the verb in the negative. Hint:
→ Can -> can't or: cannot
→ Have/has -> haven't or hasn't
→ is -> is not = isn't respectively: are -> are not = aren't
→ the rest is formed with to do: I don't see ..., he doesn't see ...
So, what fits here?
If she ________ get a taxi quickly, she ________ arrive in time at the airport.