I can't figure out why he said so.

I cannot understand why he left so suddenly.

Why don't I try to do something about the garden?

Why don't you adapt your way of life to circumstances?

Politics is the science of how who gets what, when and why.

I wonder why women live longer than men.

Why don't you pull over and take a rest for a while?

Why do you walk when you have a car?

Why don't you come to my house and play the piano?

I see no reason why I shouldn't put it into practice.