I don't have a sister. Do you have a sister? He doesn't have a sister. Does he have a sister?

No, we don't. The examples you gave are technically correct, but they are very outdated.* Nobody has actually spoken in this way for a long time! Those examples look like something from a 1950s textbook. In modern English, you have two ways of using 'have': 1. Using 'have' as an auxiliary verb and adding 'got': I haven't got a sister. Have you got a sister? He hasn't got a sister. Has he got a sister? This idiomatic use of 'have + got' is more common/acceptable in British English than in American English, but it is used everywhere. You mainly come across it in spoken English and in more informal written contexts. Note that it is only used in the present tense, and only where 'have' means 'possess': for example, you can say 'I've got a cold' but not 'I've got a shower at 6 am every day' ( here you would need to say 'I have a shower'). 2. Using the auxiliary verb 'do': I don't have a sister. Do you have a sister? He doesn't have a sister. Does he have a sister? This is the standard way of forming questions and negatives with 'have' in modern English. It is also the most useful, as it is used in all forms of English (BrE and AmE, formal and informal, written and spoken) , in all tenses (past, present etc), and all meanings of 'have' (not just possessive). * We do occasionally use the more outdated construction ('have' in its auxiliary form without 'got') when it is followed by 'any' or 'no', or in some fixed phrases e.g. 'I haven't a clue' or 'Have you any idea ...? '. These are exceptions to the rule, and you shouldn't follow this pattern. PS I have just noticed that you're an English teacher. Don't teach the examples in your post to your students!