We need it when asleep as well as when awake.

Not now, then when?

When is the intermission?

When was it finished?

When will they arrive?

When was it built?

When angry, count ten; when very angry, a hundred.

Children suck the mother when they are young, and the father when they are old.

You're really the best when, and only when, it comes to angering people.

There is no telling when they will come.