Which to use
“ui” is a noun and “un” is an article - they look or sound alike but fill different roles in a sentence.
- #23,979
- “ui” frequency rank
- #10
- “un” frequency rank
- 23989
- confusion score
Side-by-Side Comparison
| Feature | ui | un |
|---|---|---|
| Definition | Cebolla. | Artículo indeterminado masculino singular. |
Where the eye mixes ui and un
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between ui and un
These two trip readers on the page rather than in the ear: ui is [œy] while un is [ũn]. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - i in “ui” becomes n in “un”, and the parts of speech differ too (noun vs article), which is usually the fastest check. Our composite confusion score for this pair is 23989, derived from the frequency rank of both members and their visual similarity.
ui is recorded at frequency rank #23,979, classified as anoun, pronounced [œy]. un is at rank #10, tagged as anarticle, pronounced [ũn].
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 23989, this pair ranks #243,249 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of ui vs un
Shared letters: u. Private to "ui": i. Private to "un": n.
"ui" · 2 letters · shape VV · "un" · 2 letters · shape VC
Frequently Asked Questions
Can "ui" and "un" be used interchangeably?
Frequency check: "ui" vs "un" - which ranks higher?
After this comparison
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "ui" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "un" - compare definitions side by side with the headword page. Word entry
- This pair ranks #243,249 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
- "ui" and "un" also get mixed up with nearby pairs, the highest-scored neighbour is "ui vs UPN". Nearby pair
Confusion rank #243,249 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.