~ときは (when/at the time of)

When you wake up tomorrow morning, the sun will be shining and the birds will be singing.

Let me know whenever you're coming.

You've got to be careful when choosing friends.

When her mother came, she pretended to be studying.

She's careful about choosing when she's buying clothes.

You have to be careful when you're carrying a friend.

I'll contact you in advance when I come to visit.

When my mother was young, she was very beautiful.