Have as an auxiliary verb

Have is used both as an ordinary verb and as an auxiliary verb.

As an auxiliary verb

As an auxiliary verb, have is used with past participles to make perfect verb forms.

§  She has acted in a film. (Present Perfect.)

§  I have been to the US. (Present Perfect) 

§  Have you heard of the Unidentified Flying Objects? (Present Perfect) 

§  I realized that I had met him before. (Past Perfect) 

§  I will have finished this work by the end of this month. (Future Perfect) 

Questions and negatives are made without do.

§  He has gone to the market. 

§  Has he gone to the market? (NOT Does he have gone to the market.) 

§  He hasn't gone to the market. (NOT He doesn't have gone to the market.) 

§  Have you seen him before?

§  No, I haven't seen him before.

There are no progressive (having) forms of the auxiliary verb have.

§  He has gone to school. (NOT He is having gone to the school.) 

Have as an ordinary verb

As an ordinary verb, have is used to talk about states: possession, relationships, illnesses, personal characteristics and similar ideas.

§  We have a big house in the city. (Possession)

§  I have two children. (Relations) 

§  The applicant must have a good personality. (Personal characteristics) 

§  She has a nice temper. (Personal characteristics) 

§  I have a bad headache. (Illnesses) 

§  He has plenty of money, but no manners. (Possession)