The Passive Form Of Modal Auxiliaries

The passive voice of modal auxiliaries is formed by the modal + be + past participle. This formation can be used to express the present and future tenses.

• The door can’t be opened.
• Children should be taught how to read poetry.
• This package ought to be sent by tomorrow.
• Fred has to be told about the meeting.
• Jason was supposed to be informed about the changes.

The future tense

With some modals, the future tense is expressed with the auxiliary will.

• Fred will have to be told about the meeting.

The past tense

The past tense of certain modal auxiliaries in the passive voice is formed by the modal + have been + past participle.

• The letter should have been sent yesterday!
• This car must have been stolen two months ago.
• Andrew ought to have been told about the meeting.

With other modal auxiliaries, the past tense of the modal is used together with to be + past participle.

• Fred had to be told about the meeting.
• The door couldn’t be opened.