“HAVE / HAS”

Have is used in several ways. It can have the forms of an
auxiliary verb (questions and negatives without do.)

“Have you seen Alex? No, I haven’t.


It can also have the forms of an ordinary verb questions and negatives with do.

Where did you have lunch?

I don’t often have headaches.



Have is used as an auxiliary verb to make the present and past Perfect tenses.

Have you seen George anywhere?

I expected to have finished in a couple of weeks.


Have (got) to (obligation)

Have or Have got to can be used with a to + infinitive
to express the idea of obligation.

Sorry, I have got to go.

How often do you have to see the dentist?