moultvsmustWhat's the difference?

Quick tell: moult is a adverb, must is a noun, so they fill different roles in a sentence.

Which to use

“moult” is an adverb and “must” is a noun - they look or sound alike but fill different roles in a sentence.

#22,008
“moult” frequency rank
#16,189
“must” frequency rank
38197
confusion score

Side-by-Side Comparison

Feature moult must
Definition et ou Beaucoup. Note d’usage : Attaché à un verbe. Devoir incontournable ; obligation sociale.

Where the eye mixes moult and must

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.

5 ch
moult
4 ch
must

Why the eye confuses moult with must

These two trip readers on the page rather than in the ear: moult is \mu\ while must is \mœst\. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 38197, derived from the frequency rank of both members and their visual similarity.

moult is recorded at frequency rank #22,008, classified as anadv, pronounced \mu\. must is at rank #16,189, tagged as anoun, pronounced \mœst\.

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 38197, this pair ranks #256,973 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of moult vs must

Shared letters: mtu. Private to "moult": lo. Private to "must": s.

"moult" · 5 letters · shape CVVCC  ·  "must" · 4 letters · shape CVCC

Known mistypes of this pair

  • moultmmoult · molut · moullt · moultt · moutl · muolt · omult
  • mustmmust · msut · musst · mustt · muts · umst

Frequently Asked Questions

Do "moult" and "must" mean the same thing in a sentence?
No - they are not even the same part of speech. "moult" is an adverb and "must" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "moult" or "must"?
"must" is the more common of the two: it sits at frequency rank #16,189 in our French list, against #22,008 for "moult". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "moult" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "must" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #256,973 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "moult" and "must" also get mixed up with nearby pairs, the highest-scored neighbour is "moult vs Moura". 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 #256,973 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list