Overview
Passive sentences with modal verbs use modal + be + past participle. Examples: It must be checked. It should have been done. It could be improved. Modal passives are common in instructions, rules, and formal recommendations. Past modal passives use modal + have been + past participle.
Modal + Passive Structure
- presentmodal + be + past participle
- exampleIt must be checked before submission.
- exampleThis could be improved significantly.
- pastmodal + have been + past participle
- exampleIt should have been done yesterday.
Common Modal Passives
- obligationIt must be submitted by Friday.
- adviceThe form should be completed in full.
- possibilityThe error could have been avoided.
- abilityThe problem can be fixed easily.
- permissionApplications may be submitted online.
Common Mistakes
- ❌ It must be do → ✅ It must be done.
- ❌ It should be have done → ✅ It should have been done.
- ❌ It can being fixed → ✅ It can be fixed.
When to use
Instructions
The form must be completed in black ink.
Suggestions
The system could be improved significantly.
Past Regret
The error should have been caught earlier.
Permission
Applications may be submitted electronically.