Which to use
“ssi” is a conjunction and “sub” is a preposition - they look or sound alike but fill different roles in a sentence.
- #42,065
- “ssi” frequency rank
- #10,413
- “sub” frequency rank
- 52478
- confusion score
Side-by-Side Comparison
| Feature | ssi | sub |
|---|---|---|
| Definition | Abréviation de si et seulement si. | Préposition latine, qui s’emploie dans des locutions telles que : |
Where the eye mixes ssi and sub
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses ssi with sub
These two trip readers on the page rather than in the ear: ssi is \si e sœl.mɑ̃ si\ while sub is \syb\. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (conjunction vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 52478, derived from the frequency rank of both members and their visual similarity.
ssi is recorded at frequency rank #42,065, classified as aconj, pronounced \si e sœl.mɑ̃ si\. sub is at rank #10,413, tagged as aprep, pronounced \syb\.
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 52478, this pair ranks #147,450 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of ssi vs sub
Shared letters: s. Private to "ssi": i. Private to "sub": bu.
"ssi" · 3 letters · shape CCV · "sub" · 3 letters · shape CVC
Frequently Asked Questions
Is swapping "ssi" for "sub" ever safe?
In ordinary French text, does "ssi" or "sub" show up more?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "ssi" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sub" - compare definitions side by side with the headword page. Word entry
- This pair ranks #147,450 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "ssi" and "sub" also get mixed up with nearby pairs, the highest-scored neighbour is "ssi vs suu". Nearby pair
Confusion rank #147,450 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.