mustn't
MUS-uhnt/ˈmʌs.n̩t/
- 1Expresses that something is forbidden or not permitted; in a tag question, it conveys that something is not necessary.
Visitors mustn't feed the animals while walking through the sanctuary.
Look, we mustn't mistake ourselves for regular people. We're artists.
1989Note
A contraction of must with the negative -n't, where the negation falls on the action, not the obligation: you mustn't go means staying is required, not that going is optional. For "there's no need," English uses needn't instead. A tag question is a separate pattern: in We must go, mustn't we? there is no ban at all, only the positive must echoed back to the listener.
Use it in a sentence
Write your own sentence with mustn't, and AI will tell you whether it fits and which meaning you used.
Origin
Formed from "must" combined with the contraction "-n't" (short for "not").