When do you often go to sleep?
Because you sleep too late, you've got a headache.
What time do you uasually go to bed?
Late sleep makes you headache.
When do you uasually go to bed?
You feel headache because you go to bed too late.
What time do you usually go to bed?
You have a headache because you go to sleep too late at night.
when do you usually go to bed ?your headache is because you sleep too late