Select the option that expresses the given sentence in active voice. The homework must be done by you.
- (a)You will do the homework.
- (b)You should have done the homework.
- (c)You must do the homework.
- (d)You do the homework.
Answer
Why
Correct — C. The passive here is a modal passive: must + be + done.
Turn it around and three things move. The agent in by you becomes the subject You, the homework drops into object position, and the participle done returns to its base form do.
The modal must is carried across untouched — a voice change moves the players, it never rewrites the modal. That gives You must do the homework, option (c).
Why the others are wrong
- (a)You will do the homework. — Will replaces the obligation modal must with a future auxiliary. Changing voice moves the agent into subject position; it does not license a different modal, so the compulsion is lost.
- (b)You should have done the homework. — Should have done is a perfect modal, reporting a duty that was not carried out. The given sentence states an obligation that still stands.
- (d)You do the homework. — This deletes the modal altogether and leaves a plain present-simple statement. Nothing in it carries the obligation that must be done supplies.
Concept
In a voice change, three elements move and two stay put.
The passive subject becomes the object, the agent named after by becomes the subject, and the past participle returns to its base form. Tense and modality do not change.
Modal passives all follow one frame — modal + be + past participle — and their active is simply modal + base verb: can be solved becomes can solve, should be sent becomes should send, must be done becomes must do.
Once the agent becomes the subject, by goes with it. Keeping by you in the rewritten active sentence is the usual slip on this item type.
Key facts
- Modal passive frame: modal + be + past participle (must be done).
- The active of that frame is modal + base verb (must do).
- A voice change alters neither tense nor modality, so must cannot become will, should have, or nothing at all.
- The by-phrase names the agent — in the active version it becomes the subject and by disappears.
Study next
Common traps
- Softening must to will or have to because the active version then sounds smoother
- Keeping by you in the rewritten active sentence
- Leaving the participle done instead of moving to the base form do
This shift asks voice change twice: here on a modal passive, and again on a negative passive — The meal was not prepared by us (also asked 09 Sep 2024, 12:30, English Q.17).
In both, SSC builds the distractors by tampering with the auxiliary rather than with the structure, so the option that keeps tense and modality intact is the one to test first.
Related PYQs
No directly related past PYQ was found.