Present / future passive with modals

Formula: modal + be + past participle
ModalPassive formExample
mustmust be + ppThe rules must be followed.
shouldshould be + ppThe report should be submitted by Friday.
can / can'tcan/can't be + ppThis form can be downloaded online.
might / maymight/may be + ppThe decision might be delayed.
will / won'twill/won't be + ppThe package will be delivered tomorrow.
couldcould be + ppMistakes could be made if we rush.

Past passive with modals

Formula: modal + have been + past participle
ModalPast passive formExample
shouldshould have been + ppThe contract should have been signed last week.
mustmust have been + ppThe door must have been left open.
couldcould have been + ppThe accident could have been avoided.
might / maymight have been + ppThe letter might have been lost in the post.

Active → Passive: quick reference

ActivePassive
They must finish the work today.The work must be finished today.
You should check the data.The data should be checked.
Someone could have prevented this.This could have been prevented.
They should have told us.We should have been told.
By phrase: As in all passives, you can add a by phrase to show the agent when it matters: "The report must be submitted by all students before Monday."

Exercises

Choose the correct passive modal form.

1. All phones ___ during the exam. (It is obligatory.)

2. The contract ___ before the deadline — we almost missed it.

3. The results ___ published online tomorrow.

4. The accident ___ if the driver had been paying attention.

5. This medicine ___ only by a doctor. (It is not allowed otherwise.)