You're probably confused because the way we use this word in English is a little confusing! Here's a brief explanation: 1. You use 'haven't/hasn't' when the verb 'to have' is used as an AUXILIARY verb, in the present perfect and present perfect continuous tenses. Like other auxiliary verbs (be, do) and modal verbs (eg can), you form questions with an inversion 'Have you..?' 'Has he..?' and you form negatives by adding 'not' or " 'nt' ". Have you ever been to London? No, I haven't. John hasn't finished his homework yet. We haven't seen that film. 2. You treat 'have' like a normal verb when it is the MAIN verb in the sentence. You form questions with 'do/does' in the present simple and 'did' in the past, and negatives with 'don't/doesn't/didn't'. Where did you have dinner last night? Did you have a good time? No, I didn't. I didn't have a birthday party last year. 3. When you use 'have' to mean 'I own/possess' or 'It's mine/it belongs to me', you have a choice. You can use it like a main verb: Do you have a car? I don't have any brothers or sisters. She doesn't have much money Or you can use it like an auxiliary verb with the word 'got'. This form is especially common in spoken British English. It looks like a present perfect form, but in fact the word 'got' is meaningless here. These sentences mean exactly the same as the ones above: Have you got a car? I haven't got any brothers or sisters. She hasn't got much money. I hope that less confusing now!

don't have = do not have doesn't have = does not have - present simple tense. does is used for he, she it (He does not have to do it), do - for the rest of pronouns (We do not have to do it). haven't = have not + a verb in the third form - present perfect tense ( I have not done it yet) the difference between present simple and present perfect tense you can learn for example here http://www.englishpage.com/verbpage/simplepresent.html

Normally, you use "haven't" when it is the auxiliary verb (eg. haven't seen) and not the main verb. If "have" is the main verb, then the negative form is "don't have".

Hola María! Básicamente se usa "haven't" rs decir "have not" cuando "to have" es un auxiliar tal y como hacemos en español "no haber": No he ido allí: I haven't gone there. ¿No has oído eso?: Haven't you heard that? "Don't have" se usa para decir "no tener": No tengo coche: I don't have a car. (Aunque también se puede decir "I haven't got a car" si no me equivoco). ¿No tienes un mechero?: Don't you have a lighter? English native speakers, please correct me if I'm wrong.

Thank you very much!