Which to use
“must” is a verb and “muster” is a noun - they look or sound alike but fill different roles in a sentence.
- #198
- “must” frequency rank
- #16,757
- “muster” frequency rank
- 16955
- confusion score
Side-by-Side Comparison
| Feature | must | muster |
|---|---|---|
| Definition | To do as a requirement; indicates that the sentence subject is required as an imperative or directive to execute the sentence predicate, with failure to do so resulting in a failure or negative consequence. | A gathering. |
Where the eye mixes must and muster
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Look-alike desk: must vs muster
These two trip readers on the page rather than in the ear: must is /məst/ while muster is /ˈmʌs.tə/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “must” sits inside “muster”, and the parts of speech differ too (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 16955, derived from the frequency rank of both members and their visual similarity.
must is recorded at frequency rank #198, classified as averb, pronounced /məst/. muster is at rank #16,757, tagged as anoun, pronounced /ˈmʌs.tə/.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
With a confusion score of 16955, this pair ranks #454,522 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of must vs muster
Shared letters: mstu. Private to "must": -. Private to "muster": er.
"must" · 4 letters · shape CVCC · "muster" · 6 letters · shape CVCCVC
Known mistypes of this pair
Frequently Asked Questions
Can "must" and "muster" be used interchangeably?
Which is more common, "must" or "muster"?
After this comparison
Eye-level mix-up between "must" and "muster" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "must" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "muster" - compare definitions side by side with the headword page. Word entry
- This pair ranks #454,522 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "must" and "muster" also get mixed up with nearby pairs, the highest-scored neighbour is "miser vs muster". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #454,522 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.