C1vsCHTell them apart

Quick tell: C1 is a noun, CH is a symbol, so they fill different roles in a sentence.

Which to use

“C1” is a noun and “CH” is a symbol - they look or sound alike but fill different roles in a sentence.

#12,528
“C1” frequency rank
#3,389
“CH” frequency rank
15917
confusion score

Side-by-Side Comparison

Feature C1 CH
Definition Niveau de langue correspondant à un niveau expérimenté (autonome) : personne capable de comprendre des textes longs et exigeants et saisir des significations implicites ; s’exprimer spontanément et couramment sans trop devoir chercher ses mots ; utiliser la langue de façon efficace et souple dans la vie sociale, professionnelle ou académique ; s’exprimer sur des sujets complexes de façon claire et bien structurée et manifester son contrôle des outils linguistiques d'organisation, d’articulation et de cohésion du discours. Signe distinctif en trafic international des véhicules automobiles immatriculés en Suisse, prescrit dans le cadre de la Convention sur la circulation routière de Genève de 1949 et de la Convention sur la signalisation routière de Vienne de 1968.

Where the eye mixes C1 and CH

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

2 ch
C1
2 ch
CH

Why the eye confuses C1 with CH

These two trip readers on the page rather than in the ear: C1 is \se.œ̃\ while CH is voir ces lettres. En français, cela donne. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - 1 in “C1” becomes h in “CH”, and the parts of speech differ too (noun vs symbol), which is usually the fastest check. Our composite confusion score for this pair is 15917, derived from the frequency rank of both members and their visual similarity.

C1 is recorded at frequency rank #12,528, classified as anoun, pronounced \se.œ̃\. CH is at rank #3,389, tagged as asymbol, pronounced voir ces lettres. En français, cela donne.

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 15917, this pair ranks #390,265 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of C1 vs CH

Shared letters: c. Private to "C1": -. Private to "CH": h.

"C1" · 1 letters · shape C  ·  "CH" · 2 letters · shape CC

Frequently Asked Questions

Is swapping "C1" for "CH" ever safe?
No - they are not even the same part of speech. "C1" is a noun and "CH" a symbol, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "C1" or "CH"?
"CH" is the more common of the two: it sits at frequency rank #3,389 in our French list, against #12,528 for "C1". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "C1" and "CH" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "C1" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "CH" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #390,265 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "C1" and "CH" also get mixed up with nearby pairs, the highest-scored neighbour is "C1 vs CCE". Nearby pair

Confusion rank #390,265 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