osvsouWhat's the difference?

Quick tell: os is a pronoun, ou is a noun, so they fill different roles in a sentence.

Which to use

“os” is a pronoun and “ou” is a noun - they look or sound alike but fill different roles in a sentence.

#449
“os” frequency rank
#22,801
“ou” frequency rank
23250
confusion score

Side-by-Side Comparison

Feature os ou
Definition Caso acusativo y dativo del pronombre personal vosotros, una de las formas de la segunda persona del plural en español. Huevo.

Where the eye mixes os and ou

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

2 ch
os
2 ch
ou

Why the eye confuses os with ou

These two trip readers on the page rather than in the ear: os is [os] while ou is [ˈɔw]. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - s in “os” becomes u in “ou”, and the parts of speech differ too (pronoun vs noun), which is usually the fastest check. Our composite confusion score for this pair is 23250, derived from the frequency rank of both members and their visual similarity.

os is recorded at frequency rank #449, classified as apron, pronounced [os]. ou is at rank #22,801, tagged as anoun, pronounced [ˈɔw].

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 23250, this pair ranks #246,678 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of os vs ou

Shared letters: o. Private to "os": s. Private to "ou": u.

"os" · 2 letters · shape VC  ·  "ou" · 2 letters · shape VV

Frequently Asked Questions

Is swapping "os" for "ou" ever safe?
No - they are not even the same part of speech. "os" is a pronoun and "ou" a noun, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "os" vs "ou" - which ranks higher?
"os" is the more common of the two: it sits at frequency rank #449 in our Spanish list, against #22,801 for "ou". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Eye-level mix-up between "os" and "ou" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "os" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ou" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #246,678 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "os" and "ou" also get mixed up with nearby pairs, the highest-scored neighbour is "ome vs ou". Nearby pair

Confusion rank #246,678 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