catalyseurvscatalyseursWhich spelling fits?

Quick tell: catalyseur is a noun, catalyseurs is an adjective, so they fill different roles in a sentence.

Which to use

“catalyseur” is a noun and “catalyseurs” is an adjective - they look or sound alike but fill different roles in a sentence.

#21,881
“catalyseur” frequency rank
#43,830
“catalyseurs” frequency rank
65711
confusion score

Side-by-Side Comparison

Feature catalyseur catalyseurs
Definition Agent de la catalyse ; élément favorisant, voire indispensable, à une réaction chimique ou biochimique qui n’en sort pas modifié. Masculin pluriel de catalyseur.

Same sound, different letters: catalyseur vs catalyseurs

Muted letters are shared; highlighted letters are the only spelling cue when pronunciation matches. Shared run: 10 letters. catalyseur runs 10 letters (CVCVCVCVVC) against catalyseurs's 11 (CVCVCVCVVCC) - the length gap alone is often enough to separate them once you know to check it.

10 ch
catalyseur
11 ch
catalyseurs

Ear matches; page differs - catalyseur and catalyseurs

Say them out loud and nothing separates them: catalyseur and catalyseurs carry the same recorded pronunciation, \ka.ta.li.zœʁ\. Grammar is what tells them apart: one is anoun, the other anadjective, so most sentences will only accept one of them. They differ by 1 extra letter(s) - “catalyseur” sits inside “catalyseurs”. Our composite confusion score for this pair is 65711, derived from the frequency rank of both members and their visual similarity.

catalyseur is recorded at frequency rank #21,881, classified as anoun, pronounced \ka.ta.li.zœʁ\. catalyseurs is at rank #43,830, tagged as anadj, pronounced \ka.ta.li.zœʁ\.

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 65711, this pair ranks #71,099 of 440,172 scored French confusable pairs - among the most confusable pairs.

Orthographic DNA of catalyseur vs catalyseurs

Shared letters: acelrstuy. Private to "catalyseur": -. Private to "catalyseurs": -.

"catalyseur" · 10 letters · shape CVCVCVCVVC  ·  "catalyseurs" · 11 letters · shape CVCVCVCVVCC

Known mistypes of this pair

  • catalyseur ← actalyseur · caatlyseur · catallyseur · catalsyeur · catalyesur · catalyseru · catalyseurr · catalysseur
  • catalyseurs ← actalyseurs · caatlyseurs · catallyseurs · catalsyeurs · catalyesurs · catalyserus · catalyseurrs · catalyseurss

Frequently Asked Questions

Do "catalyseur" and "catalyseurs" mean the same thing in a sentence?
No - they are not even the same part of speech. "catalyseur" is a noun and "catalyseurs" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "catalyseur" vs "catalyseurs" - which ranks higher?
"catalyseur" is the more common of the two: it sits at frequency rank #21,881 in our French list, against #43,830 for "catalyseurs". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

"catalyseur" and "catalyseurs" share a sound, keep the gloss open, then jump to the headword or a nearby trap.

  • Full dictionary entry for "catalyseur" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "catalyseurs" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #71,099 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • 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 #71,099 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