In which of the following sentences does ‘must’ express a confident guess about the past?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Ravi’s room is spotless today. His mother must have cleaned it while he was at school.
Must have for a confident guess about the past:
- In Option 4, must have + past participle (V3) shows that the speaker is almost sure about a past event.
- Nobody saw the cleaning. But the spotless room makes the speaker almost sure that Ravi’s mother cleaned it.
Why the Other Options are Incorrect?
Option 1: You must try the coconut chutney at this stall. It is the best in Mysuru. — Incorrect. Here “must” gives strong advice. The speaker tells the listener something worth doing.
Option 2: Raju has been cycling uphill for an hour. He must be very thirsty. — Incorrect. “Must be” is a strong guess about the present, not the past.
Option 3: We must have the car serviced before our trip to Coorg. — Incorrect. Here “must” shows necessity. “Have the car serviced” means “get someone to service the car”, so this is not “must have + V3”.