Question

have is what part of speech

Answer 1

Have is a verb. It's an auxiliary verb.  We use it when we want to express owning something. we can use it as a main verb also.

ex:

I have two brothers and three sisters.

Do you have a camera?

Where have you been?

. 

Answer 2

Have is an irregular verb. It has 3 forms. They are: have, has and had. We use have with plural subject or plural pronouns; we, they I. We use it as an auxiliary verb and as a main verb too. The present participle is having 

ex;

I have one daughter.

We have done our homework.