Fill in the blank with the appropriate question tag:
Students must wear their ID cards inside the campus, ________?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → mustn’t they
Question tag after “must”:
Here “must” states a rule. A tag repeats the helping verb of the sentence, so the tag uses “must”. The sentence is positive, so the tag is negative: “mustn’t”. “Students” becomes “they”.
Complete sentence: Students must wear their ID cards inside the campus, mustn’t they?
Why the Other Options are Incorrect?
Option 1: don’t they — Incorrect. “Don’t” goes with a present verb that has no helping verb. Example: The twins walk to school together, don’t they?
Option 2: must they — Incorrect. This is a positive tag. It goes with a negative sentence. Example: Visitors mustn’t feed the monkeys, must they?
Option 4: mustn’t we — Incorrect. The tag uses the pronoun for the subject. “We” goes with a sentence that begins with “We”. Example: We must finish the chart by Monday, mustn’t we?