From the given alternatives, choose the one which best expresses the given sentence in Passive voice.
A child could not have done this mischief.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → This mischief could not have been done by a child.
Passive of "could not have + past participle (V3)":
| Change | Active | Passive | Why |
|---|---|---|---|
| Object becomes subject | this mischief | This mischief | This mischief receives the action, so it becomes the subject. |
| Modal form kept | could not have done | could not have been done | We keep "could not have" and add been before the V3 (done). |
| Agent (by ...) | A child | by a child | The doer goes to the end after "by". |
| Full sentence | A child could not have done this mischief. | This mischief could not have been done by a child. |
Other modal passives: can/could/must + be + V3, and could/must/may + have been + V3. Example: Someone must have taken my pen. → My pen must have been taken.
Why the Other Options are Incorrect?
Option 1: This mischief could not be done by a child. — Incorrect. It drops "have". Now it speaks of what a child is able to do, not of a past act we are judging.
Option 2: This mischief could not been done by a child. — Incorrect. "Been" cannot come straight after "could". The correct form is "could not have been".
Option 4: This mischief could not have done by a child. — Incorrect. It leaves out "been". Without "been" the verb is not in the passive.