Which to use
“once” is a noun and “ONF” is a name - they look or sound alike but fill different roles in a sentence.
- #11,815
- “once” frequency rank
- #28,271
- “ONF” frequency rank
- 40086
- confusion score
Side-by-Side Comparison
| Feature | once | ONF |
|---|---|---|
| Definition | Unité de mesure de la masse (système impérial britannique avoirdupois), qui vaut 28,3495231 grammes pour l'once commune → voir ounce. Ses symboles sont oz et ℥. L'once troy (troy ounce) équivaut pour sa part à 31,1034768 grammes. | Office national des forêts. |
Where the eye mixes once and ONF
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between once and ONF
These two trip readers on the page rather than in the ear: once is \ɔ̃s\ while ONF is \o.ɛn.ɛf\. 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 (noun vs name), which is usually the fastest check. Our composite confusion score for this pair is 40086, derived from the frequency rank of both members and their visual similarity.
once is recorded at frequency rank #11,815, classified as anoun, pronounced \ɔ̃s\. ONF is at rank #28,271, tagged as aname, pronounced \o.ɛn.ɛf\.
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 40086, this pair ranks #243,150 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of once vs ONF
Shared letters: no. Private to "once": ce. Private to "ONF": f.
"once" · 4 letters · shape VCCV · "ONF" · 3 letters · shape VCC
Known mistypes of this pair
- once ← ocne · oncce · onec · onnce
Frequently Asked Questions
Is swapping "once" for "ONF" ever safe?
Which is more common, "once" or "ONF"?
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 "once" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "ONF" - compare definitions side by side with the headword page. Word entry
- This pair ranks #243,150 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "once" and "ONF" also get mixed up with nearby pairs, the highest-scored neighbour is "och vs ONF". 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 #243,150 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.