Which to use
“si” is a conjunction and “sy” is a pronoun - they look or sound alike but fill different roles in a sentence.
- #46
- “si” frequency rank
- #15,261
- “sy” frequency rank
- 15307
- confusion score
Side-by-Side Comparison
| Feature | si | sy |
|---|---|---|
| Definition | Dans le cas où, à condition que, supposé que. Note d’usage : Conjonction qui introduit une condition (suivie d’une conséquence) ou une supposition qui peut être supprimée en utilisant un conditionnel. | Pronom personnel sujet féminin de la troisième personne du singulier : elle. |
Where the eye mixes si and sy
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between si and sy
These two trip readers on the page rather than in the ear: si is \si\ while sy is \səi\. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - i in “si” becomes y in “sy”, and the parts of speech differ too (conjunction vs pronoun), which is usually the fastest check. Our composite confusion score for this pair is 15307, derived from the frequency rank of both members and their visual similarity.
si is recorded at frequency rank #46, classified as aconj, pronounced \si\. sy is at rank #15,261, tagged as apron, pronounced \səi\.
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 15307, this pair ranks #392,925 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of si vs sy
Shared letters: s. Private to "si": i. Private to "sy": y.
"si" · 2 letters · shape CV · "sy" · 2 letters · shape CV
Frequently Asked Questions
Is swapping "si" for "sy" ever safe?
Frequency check: "si" vs "sy" - which ranks higher?
After this comparison
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "si" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sy" - compare definitions side by side with the headword page. Word entry
- This pair ranks #392,925 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "si" and "sy" also get mixed up with nearby pairs, the highest-scored neighbour is "suu vs sy". Nearby pair
Confusion rank #392,925 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.