Which to use
“sub” is a preposition and “sure” is an adjective - they look or sound alike but fill different roles in a sentence.
- #10,413
- “sub” frequency rank
- #8,164
- “sure” frequency rank
- 18577
- confusion score
Side-by-Side Comparison
| Feature | sub | sure |
|---|---|---|
| Definition | Préposition latine, qui s’emploie dans des locutions telles que : | Féminin singulier de sur : qui a un goût acide et aigrelet. |
Where the eye mixes sub and sure
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Why the eye confuses sub with sure
These two trip readers on the page rather than in the ear: sub is \syb\ while sure is \syʁ\. 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 adjective), which is usually the fastest check. Our composite confusion score for this pair is 18577, derived from the frequency rank of both members and their visual similarity.
sub is recorded at frequency rank #10,413, classified as aprep, pronounced \syb\. sure is at rank #8,164, tagged as anadj, pronounced \syʁ\.
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 18577, this pair ranks #377,606 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of sub vs sure
Shared letters: su. Private to "sub": b. Private to "sure": er.
"sub" · 3 letters · shape CVC · "sure" · 4 letters · shape CVCV
Known mistypes of this pair
- sure ← srue · ssure · surre · usre
Frequently Asked Questions
Is swapping "sub" for "sure" ever safe?
Frequency check: "sub" vs "sure" - which ranks higher?
What to do next
Eye-level mix-up between "sub" and "sure" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "sub" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sure" - compare definitions side by side with the headword page. Word entry
- This pair ranks #377,606 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "sub" and "sure" also get mixed up with nearby pairs, the highest-scored neighbour is "sub vs suu". 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 #377,606 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.