1 You don't have to/mustn't eat food in class. 2 You may/should not walk alone at night. 3 Do you must/have to wear a uniform? 4 Carrying a laptop should/can attract thieves. 5 Jane was able to/can speak French when she was six. 6 I didn't have any money, so I mustn't/couldn't buy mum a present.
1) mustn't
2) should not
3) must
4) can
5) able to
6) couldn't