oldvsosaWhich spelling fits?

Quick tell: old is a adjective, osa is a noun, so they fill different roles in a sentence.

Which to use

“old” is an adjective and “osa” is a noun - they look or sound alike but fill different roles in a sentence.

#11,277
“old” frequency rank
#22,441
“osa” frequency rank
33718
confusion score

Side-by-Side Comparison

Feature old osa
Definition Viejo, anciano. Forma del femenino singular de oso.

Where the eye mixes old and osa

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

3 ch
old
3 ch
osa

Look-alike desk: old vs osa

These two trip readers on the page rather than in the ear: old is /ˈəʊld/ while osa is [ˈosa]. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 33718, derived from the frequency rank of both members and their visual similarity.

old is recorded at frequency rank #11,277, classified as anadj, pronounced /ˈəʊld/. osa is at rank #22,441, tagged as anoun, pronounced [ˈosa].

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 33718, this pair ranks #195,264 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of old vs osa

Shared letters: o. Private to "old": dl. Private to "osa": as.

"old" · 3 letters · shape VCC  ·  "osa" · 3 letters · shape VCV

Frequently Asked Questions

Is swapping "old" for "osa" ever safe?
No - they are not even the same part of speech. "old" is an adjective and "osa" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "old" or "osa"?
"old" is the more common of the two: it sits at frequency rank #11,277 in our Spanish list, against #22,441 for "osa". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

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 "old" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "osa" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #195,264 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "old" and "osa" also get mixed up with nearby pairs, the highest-scored neighbour is "oirá vs osa". Nearby pair

Confusion rank #195,264 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