Fill in the blank choosing the correct option.
His condition is not good. He __________ see a doctor immediately.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → must
Complete sentence: His condition is not good. He must see a doctor immediately. The first sentence gives the reason ("His condition is not good"), and immediately shows urgency, so the action is a necessity.
| Option | Meaning and use | Example |
|---|---|---|
| (1) can | ability or permission. "He can see a doctor" only says that he is able to, not that he needs to. | – |
| (2) may | possibility or permission. It removes the urgency the sentence calls for. | – |
| (3) must (answer) | Must expresses strong necessity or obligation, something that has to be done. Like other modals, must is followed by the base form of the verb (see). | You must wear a seat belt while driving. |
| (4) ought | Ought is always followed by to (ought to see). "He ought see" is ungrammatical. | – |