Use "Unless" instead of "If" and versa:
1. If he doesn't hurry, he'll be late for school.
-> Unless __________________________________
2. Unless it stops raining, we won't go out.
-> _________________________________________
3. Unless he studied harder, he would fail the final exam.
-> If ________________________________________
1. Unless he hurries, he'll be late for school.
2. If it stops raining, we'll go out.
3. If he didn't study harder, he would fail the final exam.
unless he hurries, he will be late for school
if it stops raining, we will go out
if he didn't study harder, he would fail the final exam