Which to use
“op” is a preposition and “ost” is a noun - they look or sound alike but fill different roles in a sentence.
- #2,889
- “op” frequency rank
- #19,617
- “ost” frequency rank
- 22506
- confusion score
Side-by-Side Comparison
| Feature | op | ost |
|---|---|---|
| Definition | Sur. | ou Armée au Moyen Âge. |
Where the eye mixes op and ost
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses op with ost
These two trip readers on the page rather than in the ear: op is \ɔp\ while ost is \ɔst\. 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 (preposition vs noun), which is usually the fastest check. Our composite confusion score for this pair is 22506, derived from the frequency rank of both members and their visual similarity.
op is recorded at frequency rank #2,889, classified as aprep, pronounced \ɔp\. ost is at rank #19,617, tagged as anoun, pronounced \ɔst\.
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 22506, this pair ranks #357,622 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of op vs ost
Shared letters: o. Private to "op": p. Private to "ost": st.
"op" · 2 letters · shape VC · "ost" · 3 letters · shape VCC
Frequently Asked Questions
Can "op" and "ost" be used interchangeably?
In ordinary French text, does "op" or "ost" show up more?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "op" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "ost" - compare definitions side by side with the headword page. Word entry
- This pair ranks #357,622 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "op" and "ost" also get mixed up with nearby pairs, the highest-scored neighbour is "och vs ost". Nearby pair
Confusion rank #357,622 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.