There are two kinds of questions: yes or no questions and wh- questions.
You ask a yes or no question to get yes or no as the
answer. Use the verbs be, have or do, or any of the
helping verbs, to ask yes or no questions.
Can you swim? Yes.
Are they coming? No.
Is it raining? No.
May I come in? Yes.
In questions, the helping or auxiliary verbs come before
the subject of the sentence. When be and have
are used as ordinary verbs, they come before the
Wh- questions usually include the verbs be, have,
do, or any of the helping verbs.
To ask for facts, use the question words what, which,
who, whom, how, when, where. The helping verbs
in wh- questions usually come before the subject. So
does the verb be when it is used as an ordinary verb.
Where are you?
What is David saying?
How did you get up here?
Why was the girl crying?
Which color do you prefer?
Who is she going to invite to her party?
Whom is she going to invite to her party?
What is your problem?
When do the stores open in the morning?
Kaynak: Basic English Grammar Book