Which to use
“foi” is a noun and “fui” is a verb - they look or sound alike but fill different roles in a sentence.
- #1,478
- “foi” frequency rank
- #9,318
- “fui” frequency rank
- 10796
- confusion score
Side-by-Side Comparison
| Feature | foi | fui |
|---|---|---|
| Definition | Croyance aux dogmes de la religion, en Dieu. | Participe passé masculin singulier de fuir. |
Where the eye mixes foi and fui
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between foi and fui
These two trip readers on the page rather than in the ear: foi is \fwa\ while fui is \fɥi\. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - o in “foi” becomes u in “fui”, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 10796, derived from the frequency rank of both members and their visual similarity.
foi is recorded at frequency rank #1,478, classified as anoun, pronounced \fwa\. fui is at rank #9,318, tagged as averb, pronounced \fɥi\.
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 10796, this pair ranks #411,631 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of foi vs fui
Shared letters: fi. Private to "foi": o. Private to "fui": u.
"foi" · 3 letters · shape CVV · "fui" · 3 letters · shape CVV
Frequently Asked Questions
Can "foi" and "fui" be used interchangeably?
Which is more common, "foi" or "fui"?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "foi" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fui" - compare definitions side by side with the headword page. Word entry
- This pair ranks #411,631 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "foi" and "fui" also get mixed up with nearby pairs, the highest-scored neighbour is "Fee vs fui". Nearby pair
Confusion rank #411,631 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.