1. When I study for six hours I feel exhausted.
I feel exhausted when I study for six hours.
2. I talk to my friend when I have a problem.
When I have a problem, I talk to my friend.
3. When I go on vacation, I sleep very late.
I sleep very late when I go on vacation.
4. When I look at the mountains, I feel calm.
I feel calm when I look at the mountains.
5. I take aspirin when I have a headache.
When I have a headache, I take aspirin.