Which to use
“fallu” is a verb and “fau” is a noun - they look or sound alike but fill different roles in a sentence.
- #3,331
- “fallu” frequency rank
- #38,799
- “fau” frequency rank
- 42130
- confusion score
Side-by-Side Comparison
| Feature | fallu | fau |
|---|---|---|
| Definition | Participe passé de falloir. | ou Hêtre, plus particulièrement le hêtre tortillard (Fagus sylvatica). |
Where the eye mixes fallu and fau
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Look-alike desk: fallu vs fau
These two trip readers on the page rather than in the ear: fallu is \fa.ly\ while fau is \fo\. 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 (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 42130, derived from the frequency rank of both members and their visual similarity.
fallu is recorded at frequency rank #3,331, classified as averb, pronounced \fa.ly\. fau is at rank #38,799, tagged as anoun, pronounced \fo\.
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 42130, this pair ranks #228,000 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fallu vs fau
Shared letters: afu. Private to "fallu": l. Private to "fau": -.
"fallu" · 5 letters · shape CVCCV · "fau" · 3 letters · shape CVV
Known mistypes of this pair
- fallu ← afllu · falu · falul · ffallu · flalu
Frequently Asked Questions
Can "fallu" and "fau" be used interchangeably?
In ordinary French text, does "fallu" or "fau" show up more?
Useful next steps
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "fallu" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fau" - compare definitions side by side with the headword page. Word entry
- This pair ranks #228,000 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "fallu" and "fau" also get mixed up with nearby pairs, the highest-scored neighbour is "fau vs Fee". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #228,000 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.