Modal verbs — permission, obligation, prohibition, necessity

You ___ disclose this password; it is prohibited.

Your answer: Unanswered

Correct answer: mustn't

Completed sentence: You mustn't disclose this password; it is prohibited. Distinguish permission, obligation, prohibition and lack of necessity. Mustn't prohibits; needn't removes necessity. Needn't have describes unnecessary completed action; didn't need to only states absence of necessity. Be allowed to and have to supply forms unavailable to some modals.

We ___ have booked; there were plenty of seats. (we did book)

Your answer: Unanswered

Correct answer: needn't

Completed sentence: We needn't have booked; there were plenty of seats. (we did book) Distinguish permission, obligation, prohibition and lack of necessity. Mustn't prohibits; needn't removes necessity. Needn't have describes unnecessary completed action; didn't need to only states absence of necessity. Be allowed to and have to supply forms unavailable to some modals.

She had ___ show identification.

Your answer: Unanswered

Correct answer: to

Completed sentence: She had to show identification. Distinguish permission, obligation, prohibition and lack of necessity. Mustn't prohibits; needn't removes necessity. Needn't have describes unnecessary completed action; didn't need to only states absence of necessity. Be allowed to and have to supply forms unavailable to some modals.

Will we be allowed ___ leave early?

Your answer: Unanswered

Correct answer: to

Completed sentence: Will we be allowed to leave early? Distinguish permission, obligation, prohibition and lack of necessity. Mustn't prohibits; needn't removes necessity. Needn't have describes unnecessary completed action; didn't need to only states absence of necessity. Be allowed to and have to supply forms unavailable to some modals.

You ___ attend; it's entirely optional.

Your answer: Unanswered

Correct answer: don't have to

Completed sentence: You don't have to attend; it's entirely optional. Distinguish permission, obligation, prohibition and lack of necessity. Mustn't prohibits; needn't removes necessity. Needn't have describes unnecessary completed action; didn't need to only states absence of necessity. Be allowed to and have to supply forms unavailable to some modals.