seu vs si, What's the Difference?

Which to use

“seu” is an adjective and “si” is a conjunction - they look or sound alike but fill different roles in a sentence.

#35,274
“seu” frequency rank: #46
“si” frequency rank: 35320
confusion score

Side-by-Side Comparison

Feature	seu	si
Definition	Sa, son.	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.

Letter map: seu vs si

Shared letters muted; letters that set seu and si apart highlighted. Shared run: 1.

3 ch

seu

2 ch

Role in the sentence - seu and si

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: seu is anadjective and siaconjunction. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 35320, derived from the frequency rank of both members and their visual similarity.

seu is recorded at frequency rank #35,274, classified as anadj. si is at rank #46, tagged as aconj, 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 35320, this pair ranks #277,587 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of seu vs si

Shared letters: s. Private to "seu": eu. Private to "si": i.

"seu" · 3 letters · shape CVV · "si" · 2 letters · shape CV

Frequently Asked Questions

Do "seu" and "si" mean the same thing in a sentence?

No - they are not even the same part of speech. "seu" is an adjective and "si" a conjunction, so a sentence built for one is usually ungrammatical with the other.

In ordinary French text, does "seu" or "si" show up more?

"si" is the more common of the two: it sits at frequency rank #46 in our French list, against #35,274 for "seu". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "seu" and "si".

Full dictionary entry for "seu" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "si" - compare definitions side by side with the headword page. Word entry
This pair ranks #277,587 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"seu" and "si" also get mixed up with nearby pairs, the highest-scored neighbour is "seu vs suu". Nearby pair

Confusion rank #277,587 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.