When you have to go to school, what time do you wake up?
Example: When I have to go to school, I wake up at 6am. / I wake up at 6am if I have to go to school.
If you have free time, what do you like to do?
Example: If I have free time, I like to read. / I like to read if I have free time.
If you combine hot oil and water, what happens?
Example: If you combine oil and water, you get a mixture.