Which to use
“cas” is a noun and “ci” is an adverb - they look or sound alike but fill different roles in a sentence.
- #157
- “cas” frequency rank
- #264
- “ci” frequency rank
- 421
- confusion score
Side-by-Side Comparison
| Feature | cas | ci |
|---|---|---|
| Definition | Accident, aventure, conjoncture, occasion ; fait arrivé, ou qui peut arriver. | ou (Utilisé uniquement dans les compositions, pas utilisé isolément) Ici. |
Where the eye mixes cas and ci
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between cas and ci
These two trip readers on the page rather than in the ear: cas is \kɑ\ while ci is \si\. 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 (noun vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 421, derived from the frequency rank of both members and their visual similarity.
cas is recorded at frequency rank #157, classified as anoun, pronounced \kɑ\. ci is at rank #264, tagged as anadv, pronounced \si\.
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 421, this pair ranks #439,671 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of cas vs ci
Shared letters: c. Private to "cas": as. Private to "ci": i.
"cas" · 3 letters · shape CVC · "ci" · 2 letters · shape CV
Frequently Asked Questions
Is swapping "cas" for "ci" ever safe?
Which is more common, "cas" or "ci"?
After this comparison
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "cas" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "ci" - compare definitions side by side with the headword page. Word entry
- This pair ranks #439,671 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "cas" and "ci" also get mixed up with nearby pairs, the highest-scored neighbour is "ci vs ciro". Nearby pair
Confusion rank #439,671 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.