oncevsontWhich spelling fits?

Quick tell: once is a noun, ont is a verb, so they fill different roles in a sentence.

Which to use

“once” is a noun and “ont” is a verb - they look or sound alike but fill different roles in a sentence.

#11,815
“once” frequency rank
#61
“ont” frequency rank
11876
confusion score

Side-by-Side Comparison

Feature once ont
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. Troisième personne du pluriel de l’indicatif présent du verbe avoir.

Where the eye mixes once and ont

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
once
3 ch
ont

Look-alike desk: once vs ont

These two trip readers on the page rather than in the ear: once is \ɔ̃s\ while ont is \ɔ̃\. 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 verb), which is usually the fastest check. Our composite confusion score for this pair is 11876, 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\. ont is at rank #61, tagged as averb, pronounced \ɔ̃\.

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 11876, this pair ranks #407,494 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of once vs ont

Shared letters: no. Private to "once": ce. Private to "ont": t.

"once" · 4 letters · shape VCCV  ·  "ont" · 3 letters · shape VCC

Known mistypes of this pair

  • onceocne · oncce · onec · onnce

Frequently Asked Questions

Can "once" and "ont" be used interchangeably?
No - they are not even the same part of speech. "once" is a noun and "ont" a verb, so a sentence built for one is usually ungrammatical with the other.
In ordinary French text, does "once" or "ont" show up more?
"ont" is the more common of the two: it sits at frequency rank #61 in our French list, against #11,815 for "once". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Eye-level mix-up between "once" and "ont" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "once" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ont" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #407,494 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "once" and "ont" also get mixed up with nearby pairs, the highest-scored neighbour is "och vs once". 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 #407,494 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list