Has, have and had can be used both as auxiliaries and as principal verbs. When they are used as auxiliaries they help in the formation of present perfect and past perfect tenses.

Questions are formed by putting the auxiliary before the subject. Negatives are formed by putting not after the auxiliary.

I have seen her.
Have I seen her?
I have not seen her. OR I haven’t seen her.

I had told him that.
Had I told him that?
I had not told him that.

He has come.
Has he come?
He has not come.

They have arrived.
Have they arrived?
They have not arrived.

When has, have and had are used as principal verbs, expressing the idea of possession – either of material things or of characteristic features – questions and negatives may be formed with or without do.

She has a sweet voice.
Has she a sweet voice? OR Does she have a sweet voice?
She hasn’t a sweet voice. OR She doesn’t have a sweet voice.

I have a sister.
Have you a sister? OR Do you have a sister?
I haven’t a sister. OR I don’t have a sister.

She has curly hair.
Has she curly hair? Does she have curly hair?
She hasn’t curly hair. OR She doesn’t have curly hair.
Notes
Questions and negatives with do are more common than questions and negatives without do.

When have is used to express other ideas (e.g. receive, experience, take etc.), questions and negatives are made with do.

I had (= experienced) an accident.
Did I have an accident? (NOT Had I an accident?)
I didn’t have an accident. (NOT I hadn’t an accident.)

I had (= received) a letter from my son.
Did I have a letter from my son? (NOT Had I a letter from my son?)
I didn’t have a letter from my son. (NOT I hadn’t a letter from my son.)

I have (= take) a bath in the morning.
Do I have a bath in the morning?
I don’t have a bath in the morning.