aptavsarcaWhich spelling fits?

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

Which to use

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

#20,890
“apta” frequency rank
#12,304
“arca” frequency rank
33194
confusion score

Side-by-Side Comparison

Feature apta arca
Definition Forma del femenino singular de apto. Caja que puede tener distintos tamaños, generalmente de madera, cuya tapa se asegura con bisagras por uno de sus lados y que suele cerrarse con cerradura y candado. Suele estar muy ornamentada y a veces reposa sobre un pequeño podium.

Where the eye mixes apta and arca

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

4 ch
apta
4 ch
arca

Visual trap between apta and arca

These two trip readers on the page rather than in the ear: apta is [ˈapt̪a] while arca is [ˈaɾka]. 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 33194, derived from the frequency rank of both members and their visual similarity.

apta is recorded at frequency rank #20,890, classified as anadj, pronounced [ˈapt̪a]. arca is at rank #12,304, tagged as anoun, pronounced [ˈaɾka].

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 33194, this pair ranks #198,103 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of apta vs arca

Shared letters: a. Private to "apta": pt. Private to "arca": cr.

"apta" · 4 letters · shape VCCV  ·  "arca" · 4 letters · shape VCCV

Known mistypes of this pair

  • aptaapat · appta · aptta
  • arcaarac · arcca · arrca · raca

Frequently Asked Questions

Is swapping "apta" for "arca" ever safe?
No - they are not even the same part of speech. "apta" is an adjective and "arca" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary Spanish text, does "apta" or "arca" show up more?
"arca" is the more common of the two: it sits at frequency rank #12,304 in our Spanish list, against #20,890 for "apta". 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 "apta" and "arca" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "apta" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "arca" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #198,103 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "apta" and "arca" also get mixed up with nearby pairs, the highest-scored neighbour is "apis vs apta". 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 #198,103 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