muvsmustWhich spelling fits?

Which to use

“mu” and “must” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#14,985
“mu” frequency rank
#16,189
“must” frequency rank
31174
confusion score

Side-by-Side Comparison

Feature mu must
Definition μ, Μ, douzième lettre et huitième consonne de l’alphabet grec. Devoir incontournable ; obligation sociale.

Where the eye mixes mu and must

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

2 ch
mu
4 ch
must

Look-alike desk: mu vs must

A purely visual mix-up. mu (\my\) and must (\mœst\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 2 extra letter(s) - “mu” sits inside “must”. Our composite confusion score for this pair is 31174, derived from the frequency rank of both members and their visual similarity.

mu is recorded at frequency rank #14,985, classified as anoun, pronounced \my\. 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 31174, this pair ranks #305,511 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of mu vs must

Shared letters: mu. Private to "mu": -. Private to "must": st.

"mu" · 2 letters · shape CV  ·  "must" · 4 letters · shape CVCC

Known mistypes of this pair

  • mustmmust · msut · musst · mustt · muts · umst

Frequently Asked Questions

Can "mu" and "must" be used interchangeably?
No. They are said differently (\my\ versus \mœst\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary French text, does "mu" or "must" show up more?
"mu" is the more common of the two: it sits at frequency rank #14,985 in our French list, against #16,189 for "must". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "mu" 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 #305,511 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "mu" and "must" also get mixed up with nearby pairs, the highest-scored neighbour is "mud vs must". 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 #305,511 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