Which to use
“sœur” is a noun and “su” is a verb - they look or sound alike but fill different roles in a sentence.
- #1,380
- “sœur” frequency rank
- #1,609
- “su” frequency rank
- 2989
- confusion score
Side-by-Side Comparison
| Feature | sœur | su |
|---|---|---|
| Definition | Femme ou fille, ayant le même père et la même mère que la personne considérée. Si un seul des parents est commun, c’est une demi-sœur. | Participe passé masculin singulier du verbe savoir. |
Where the spellings diverge
Shared letters are muted; the letters that actually set sœur and su apart are highlighted. They share 2 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
These two trip readers on the page rather than in the ear: sœur is \sœʁ\ while su is \sy\. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 letter(s) in length, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 2989, derived from the frequency rank of both members and their visual similarity.
sœur is recorded at frequency rank #1,380, classified as anoun, pronounced \sœʁ\. su is at rank #1,609, tagged as averb, pronounced \sy\.
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 2989, this pair ranks #435,045 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of sœur vs su
Shared letters: su. Private to "sœur": rœ. Private to "su": -.
"sœur" · 4 letters · shape CVVC · "su" · 2 letters · shape CV
Frequency comparison
Frequently Asked Questions
Can "sœur" and "su" be used interchangeably?
Which is more common, "sœur" or "su"?
Remembering sœur vs su
The fastest way to pick the right one every time.
- Check the role first: if you need a noun, it's “sœur”; for a verb, it's “su”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “sœur” entry
- Browse more pairs most likely to be confused. Most confusable