Which to use
“sei” is a verb and “si” is a conjunction - they look or sound alike but fill different roles in a sentence.
- #36,154
- “sei” frequency rank
- #46
- “si” frequency rank
- 36200
- confusion score
Side-by-Side Comparison
| Feature | sei | si |
|---|---|---|
| Definition | Deuxième personne du singulier de l’impératif présent de sein. | 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. |
Where the spellings diverge
Shared letters are muted; the letters that actually set sei and si apart are highlighted. They share 2 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
sei and si form a confusable pair in the French index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 1 letter(s) in length - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 36200, derived from the frequency rank of both members and their visual similarity.
sei is recorded at frequency rank #36,154, classified as averb, pronounced \zaɪ̯\. 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 36200, this pair ranks #271,303 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Frequency comparison
Frequently Asked Questions
Can "sei" and "si" be used interchangeably?
Remembering sei vs si
The fastest way to pick the right one every time.
- Check the role first: if you need a verb, it's “sei”; for a conjunction, it's “si”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “sei” entry
- Browse more pairs most likely to be confused. Most confusable