The word have is a verb, meaning to be in posession of, or own or contain something. So depending on your sentence, it would go like this: I have a cat. You have a cat. He/She has a cat. (Notice that have changes to has for the he or she form) We have a cat. They have a cat. Had is the past tense of have. It means you used to be in possession of, own or contain something, and you do not it anymore. I/You/He/She/We/They had a cat. (It is the same for all of them) Have been is more of a phrase using the above combinations. I have been to Costa Rica. - This is used to show that you have gone somewhere or done something.