If there is a question word (why, what, where, how, etc.), it goes before the verb.

Question

Are you late?

Question with question word

Why are you late?

Question

Was she there?

Question with question word

When was she there?

Question

Can I help?

Question with question word

How can I help?

Question

Have we met before?

Question with question word

Where have we met before?

This is true for sentences with be, sentences that have auxiliary verbs (e.g. They are waiting. She has finished.) and sentences with modal verbs (can, will, should, might, etc.).