'Don't have' translates as 'no tengo' . eg I don't have time / I don't have any brothers or sisters so that isn't possible here. In your sentence about the exam, you can answer either: I didn't pass = past simple or I haven't passed = present perfect These are similar in meaning, and would depend on the context. If you're not sure whether to use the past or the present perfect, I'd advise you to use the past. It's more likely to be correct, especially in US English. I hope that helps.

Can I add something which I didn't explain in the previous post? The verb 'to have' basically has two ways of conjugating: 1. When it means to (more or less) to possess (I have a bicycle) Affirmative : I have ..... Negative: I don't have ... Question: Do you have ...? 2. When it is acting as an auxiliary verb ( I have eaten) Affirmative : I have eaten Negative: I haven't eaten Question: Have you eaten? So the reason that your first example ("I don't have passed my exam") is wrong is because you were using the wrong conjugation of the verb to have. You were using the first conjugation, when you should have used the auxiliary form. I hope that solves your problem.

I haven't passed my exam. The first one should read "I didn't pass my exam".

What you need to remember is that contractions are a combination of two words. Just separate the contraction into 2 words and then you will see if it is correct or not. In this case "I do not have passed my exam" or "I have not passed my exam". The correct version should be clear. I agree with Su.Ki. that the past simple would be the best: "I didn't pass my exam."