Which to use
“lui” is a pronoun and “lux” is a noun - they look or sound alike but fill different roles in a sentence.
- #68
- “lui” frequency rank
- #18,246
- “lux” frequency rank
- 18314
- confusion score
Side-by-Side Comparison
| Feature | lui | lux |
|---|---|---|
| Definition | Pronom clitique de la troisième personne du singulier épicène du complément d’objet indirect. | Unité de mesure d’éclairement lumineux du Système international, définie comme lumen par mètre carré, dont le symbole est lx. |
Where the eye mixes lui and lux
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Why the eye confuses lui with lux
These two trip readers on the page rather than in the ear: lui is \lɥi\ while lux is \lyks\. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - i in “lui” becomes x in “lux”, and the parts of speech differ too (pronoun vs noun), which is usually the fastest check. Our composite confusion score for this pair is 18314, derived from the frequency rank of both members and their visual similarity.
lui is recorded at frequency rank #68, classified as apron, pronounced \lɥi\. lux is at rank #18,246, tagged as anoun, pronounced \lyks\.
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 18314, this pair ranks #378,949 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of lui vs lux
Shared letters: lu. Private to "lui": i. Private to "lux": x.
"lui" · 3 letters · shape CVV · "lux" · 3 letters · shape CVC
Frequently Asked Questions
Do "lui" and "lux" mean the same thing in a sentence?
In ordinary French text, does "lui" or "lux" show up more?
Useful next steps
Eye-level mix-up between "lui" and "lux" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "lui" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "lux" - compare definitions side by side with the headword page. Word entry
- This pair ranks #378,949 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "lui" and "lux" also get mixed up with nearby pairs, the highest-scored neighbour is "lep vs lux". Nearby pair
Confusion rank #378,949 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.