(EEAR - 2018/1)
The modal verbs underlined in each sentence express:
1 – She might be at the party.
2 – Can you drive a dump truck?
3 – He mustn’t sleep during the class.
4 – You ought to learn Aviation English.
ability, possibility, advice, prohibition
possibility, ability, prohibition, advice
permission, possibility, request, wish
ability, request, prohibition, offers