algavsalgúnWhich spelling fits?

Quick tell: alga is a noun, algún is an adjective, so they fill different roles in a sentence.

Which to use

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

#34,872
“alga” frequency rank
#315
“algún” frequency rank
35187
confusion score

Side-by-Side Comparison

Feature alga algún
Definition Organismo acuático autótrofo —es decir, capaz de fotosíntesis—, sea procarionte o eucarionte. No forman un grupo taxonómico homogéneo, comprendiendo desde organismos unicelulares muy sencillos hasta enormes colonias de decenas de metros de longitud. Se clasifican en al menos nueve filos, de uno de los cuales proceden evolutivamente las plantas propiamente dichas. Variante de alguno.

Where the eye mixes alga and algún

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.

4 ch
alga
5 ch
algún

Why the eye confuses alga with algún

These two trip readers on the page rather than in the ear: alga is [ˈalɣ̞a] while algún is [alˈɣ̞ũn]. 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 (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 35187, derived from the frequency rank of both members and their visual similarity.

alga is recorded at frequency rank #34,872, classified as anoun, pronounced [ˈalɣ̞a]. algún is at rank #315, tagged as anadj, pronounced [alˈɣ̞ũn].

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 35187, this pair ranks #187,430 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of alga vs algún

Shared letters: agl. Private to "alga": -. Private to "algún": .

"alga" · 4 letters · shape VCCV  ·  "algún" · 5 letters · shape VCCVC

Known mistypes of this pair

  • algaalag · algga · allga · laga

Frequently Asked Questions

Is swapping "alga" for "algún" ever safe?
No - they are not even the same part of speech. "alga" is a noun and "algún" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "alga" vs "algún" - which ranks higher?
"algún" is the more common of the two: it sits at frequency rank #315 in our Spanish list, against #34,872 for "alga". 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 "alga" and "algún" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "alga" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "algún" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #187,430 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "alga" and "algún" also get mixed up with nearby pairs, the highest-scored neighbour is "alga vs anta". 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 #187,430 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