undvsunoWhich spelling fits?

Quick tell: und is a conjunction, uno is a num, so they fill different roles in a sentence.

Which to use

“und” is a conjunction and “uno” is a num - they look or sound alike but fill different roles in a sentence.

#14,978
“und” frequency rank
#77
“uno” frequency rank
15055
confusion score

Side-by-Side Comparison

Feature und uno
Definition Y. La cantidad de una cosa solitaria (a saber, sin otros).

Where the eye mixes und and uno

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

3 ch
und
3 ch
uno

Visual trap between und and uno

These two trip readers on the page rather than in the ear: und is /ʊnt/ while uno is [ˈuno]. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - d in “und” becomes o in “uno”, and the parts of speech differ too (conjunction vs num), which is usually the fastest check. Our composite confusion score for this pair is 15055, derived from the frequency rank of both members and their visual similarity.

und is recorded at frequency rank #14,978, classified as aconj, pronounced /ʊnt/. uno is at rank #77, tagged as anum, pronounced [ˈuno].

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 15055, this pair ranks #281,672 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of und vs uno

Shared letters: nu. Private to "und": d. Private to "uno": o.

"und" · 3 letters · shape VCC  ·  "uno" · 3 letters · shape VCV

Frequently Asked Questions

Can "und" and "uno" be used interchangeably?
No - they are not even the same part of speech. "und" is a conjunction and "uno" a num, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "und" vs "uno" - which ranks higher?
"uno" is the more common of the two: it sits at frequency rank #77 in our Spanish list, against #14,978 for "und". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "und" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "uno" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #281,672 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "und" and "uno" also get mixed up with nearby pairs, the highest-scored neighbour is "und vs UPN". Nearby pair

Confusion rank #281,672 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list