ácidosvsactivosTell them apart

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

Which to use

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

#12,079
“ácidos” frequency rank
#2,857
“activos” frequency rank
14936
confusion score

Side-by-Side Comparison

Feature ácidos activos
Definition Forma del masculino plural de ácido. Forma del plural de activo.

Where the eye mixes ácidos and activos

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence. ácidos runs 6 letters (VCVCVC) against activos's 7 (VCCVCVC) - the length gap alone is often enough to separate them once you know to check it.

6 ch
ácidos
7 ch
activos

Look-alike desk: ácidos vs activos

These two trip readers on the page rather than in the ear: ácidos is [ˈasið̞os] while activos is [akˈt̪iβ̞os]. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 14936, derived from the frequency rank of both members and their visual similarity.

ácidos is recorded at frequency rank #12,079, classified as anadj, pronounced [ˈasið̞os]. activos is at rank #2,857, tagged as anoun, pronounced [akˈt̪iβ̞os].

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 14936, this pair ranks #282,147 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ácidos vs activos

Shared letters: cios. Private to "ácidos": dá. Private to "activos": atv.

"ácidos" · 6 letters · shape VCVCVC  ·  "activos" · 7 letters · shape VCCVCVC

Known mistypes of this pair

  • activos ← acctivos · acitvos · actibos · actiovs · activoss · activso · activvos · acttivos

Frequently Asked Questions

Is swapping "ácidos" for "activos" ever safe?
No - they are not even the same part of speech. "ácidos" is an adjective and "activos" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ácidos" or "activos"?
"activos" is the more common of the two: it sits at frequency rank #2,857 in our Spanish list, against #12,079 for "ácidos". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

  • Full dictionary entry for "ácidos" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "activos" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #282,147 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "ácidos" and "activos" also get mixed up with nearby pairs, the highest-scored neighbour is "ácidos vs ávidos". 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 #282,147 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