Which to use
“fast” is an adverb and “fault” is a verb - they look or sound alike but fill different roles in a sentence.
- #8,544
- “fast” frequency rank
- #46,753
- “fault” frequency rank
- 55297
- confusion score
Side-by-Side Comparison
| Feature | fast | fault |
|---|---|---|
| Definition | Presque, quasiment. | Deuxième personne du pluriel de l’impératif présent de faulen. |
Where the eye mixes fast and fault
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. fast runs 4 letters (CVCC) against fault's 5 (CVVCC) - the length gap alone is often enough to separate them once you know to check it.
Visual trap between fast and fault
These two trip readers on the page rather than in the ear: fast is \fast\ while fault is \faʊ̯lt\. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adverb vs verb), which is usually the fastest check. Our composite confusion score for this pair is 55297, derived from the frequency rank of both members and their visual similarity.
fast is recorded at frequency rank #8,544, classified as anadv, pronounced \fast\. fault is at rank #46,753, tagged as averb, pronounced \faʊ̯lt\.
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 55297, this pair ranks #128,358 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fast vs fault
Shared letters: aft. Private to "fast": s. Private to "fault": lu.
"fast" · 4 letters · shape CVCC · "fault" · 5 letters · shape CVVCC
Known mistypes of this pair
Frequently Asked Questions
Can "fast" and "fault" be used interchangeably?
In ordinary French text, does "fast" or "fault" show up more?
After this comparison
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "fast" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fault" - compare definitions side by side with the headword page. Word entry
- This pair ranks #128,358 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "fast" and "fault" also get mixed up with nearby pairs, the highest-scored neighbour is "fau vs fault". 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 #128,358 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.