castasvscastorWhich spelling fits?

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

Which to use

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

#17,066
“castas” frequency rank
#24,417
“castor” frequency rank
41483
confusion score

Side-by-Side Comparison

Feature castas castor
Definition Forma del femenino plural de casto. Castor canadensis. Animal que hace diques, con gran daño para el entorno. Por ejempo, en Tierra del Fuego el castor es una plaga

Where the eye mixes castas and castor

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence. castas and castor follow the identical consonant-vowel pattern (CVCCVC). Same shape at a glance is often the real trap, independent of shared letters.

6 ch
castas
6 ch
castor

Visual trap between castas and castor

These two trip readers on the page rather than in the ear: castas is [ˈkast̪as] while castor is [kasˈt̪oɾ]. 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 41483, derived from the frequency rank of both members and their visual similarity.

castas is recorded at frequency rank #17,066, classified as anadj, pronounced [ˈkast̪as]. castor is at rank #24,417, tagged as anoun, pronounced [kasˈt̪oɾ].

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 41483, this pair ranks #153,381 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of castas vs castor

Shared letters: acst. Private to "castas": -. Private to "castor": or.

"castas" · 6 letters · shape CVCCVC  ·  "castor" · 6 letters · shape CVCCVC

Known mistypes of this pair

  • castasacstas · casats · casstas · castass · castsa · casttas · catsas · ccastas
  • castoracstor · casotr · casstor · castorr · casttor · catsor · ccastor · csator

Frequently Asked Questions

Is swapping "castas" for "castor" ever safe?
No - they are not even the same part of speech. "castas" is an adjective and "castor" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "castas" or "castor"?
"castas" is the more common of the two: it sits at frequency rank #17,066 in our Spanish list, against #24,417 for "castor". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

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

  • Full dictionary entry for "castas" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "castor" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #153,381 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "castas" and "castor" also get mixed up with nearby pairs, the highest-scored neighbour is "castor vs castores". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #153,381 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