4 задание не понимаю правила has, hasn’t, have, haven’t

Правильно молодец

1) have / have2) has/ hasn't 3)has/has4) have/haven't

Have they got a computet?Yes they haveHas he got a sister?No he hasn'tHas tom got a pen in his school bag?Yes he hasHave you got a computer?No i haven't