Verbs of perception like see and hear, and the causative make, change the bare infinitive after the object in the active into a to-infinitive in the passive, as in he was seen to leave. The -ing form stays unchanged, and causative let has no direct passive, substituted by be allowed to.
Grammar Rule
Verbs of perception (see, hear, watch, notice) and causative make follow a special rule in the passive: the bare infinitive after the object in the active becomes a to-infinitive in the passive. When the active uses the -ing form (action in progress), it stays unchanged. Causative let has no direct passive; English substitutes be allowed to.
Passive Voice with Verbs of Perception and Causatives: Rules and Examples
| Active | Passive | Example |
|---|---|---|
| see/hear + object + bare infinitive | be seen/heard + to-infinitive | He was seen to leave. |
| see/hear + object + -ing | -ing form stays unchanged | He was seen leaving the building. |
| make + object + bare infinitive | be made + to-infinitive | The interns were made to redo the report. |
| let + object + bare infinitive | be allowed to (no direct passive) | He was allowed to leave early. |
Remember: After passive perception verbs and make, the bare infinitive becomes to plus infinitive; let becomes be allowed to.
Practice Test
Instructions
Answer each question in the test below using the passive with perception verbs and causatives correctly. You will get a new random set of questions every time you retake the test, plus a downloadable results summary with your name and score at the end.
C1-21 Passive Voice: Perception Verbs and Causatives
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Frequently Asked Questions
What happens to the bare infinitive after see/hear in the passive?
It becomes a to-infinitive, as in he was seen to leave.
What happens to the -ing form after see/hear in the passive?
It stays unchanged, as in he was seen leaving the building.
What happens to make plus object plus bare infinitive in the passive?
It becomes be made plus to-infinitive, as in the interns were made to redo the report.
Does causative let have a direct passive?
No, English substitutes be allowed to, as in he was allowed to leave early.