have

Someone has something if the thing is in their hands. The person is holding or gripping it.

Example: Do you have a spoon, or do you need me to give you one so you can eat the soup?

If you have to do something, you must do it.

Example: I have to go.

Someone has something if the thing is that person's thing: the person owns it; it belongs to the person.

Example: The rich family has a big house.

If you have you hold something in the mind.

Example: I have a doubt about him.

If you have you join something.

Example: We have lunch at 13:00.