Which to use
“ui” is a noun and “und” is a conjunction - they look or sound alike but fill different roles in a sentence.
- #23,979
- “ui” frequency rank
- #14,978
- “und” frequency rank
- 38957
- confusion score
Side-by-Side Comparison
| Feature | ui | und |
|---|---|---|
| Definition | Cebolla. | Y. |
Where the eye mixes ui and und
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses ui with und
These two trip readers on the page rather than in the ear: ui is [œy] while und is /ʊnt/. 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 conjunction), which is usually the fastest check. Our composite confusion score for this pair is 38957, 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]. und is at rank #14,978, tagged as aconj, pronounced /ʊnt/.
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 38957, this pair ranks #167,185 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of ui vs und
Shared letters: u. Private to "ui": i. Private to "und": dn.
"ui" · 2 letters · shape VV · "und" · 3 letters · shape VCC
Frequently Asked Questions
Is swapping "ui" for "und" ever safe?
In ordinary Spanish text, does "ui" or "und" show up more?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "ui" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "und" - compare definitions side by side with the headword page. Word entry
- This pair ranks #167,185 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
- "ui" and "und" also get mixed up with nearby pairs, the highest-scored neighbour is "ui vs UPN". Nearby pair
Confusion rank #167,185 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.