ajvsaúnWhat's the difference?

Quick tell: aj is a noun, aún is an adverb, so they fill different roles in a sentence.

Which to use

“aj” is a noun and “aún” is an adverb - they look or sound alike but fill different roles in a sentence.

#21,891
“aj” frequency rank
#240
“aún” frequency rank
22131
confusion score

Side-by-Side Comparison

Feature aj aún
Definition Síndrome o enfermedad crónica, causada por la vejez u otra condición estable. Indica que el hecho persiste en el presente, aunque pueda cambiar en lo sucesivo..

Where the eye mixes aj and aún

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

2 ch
aj
3 ch
aún

Visual trap between aj and aún

These two trip readers on the page rather than in the ear: aj is [ˈaks] while aún is [aˈũn]. 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 adverb), which is usually the fastest check. Our composite confusion score for this pair is 22131, derived from the frequency rank of both members and their visual similarity.

aj is recorded at frequency rank #21,891, classified as anoun, pronounced [ˈaks]. aún is at rank #240, tagged as anadv, pronounced [aˈũn].

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 22131, this pair ranks #251,768 of 323,831 scored Spanish confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of aj vs aún

Shared letters: a. Private to "aj": j. Private to "aún": .

"aj" · 2 letters · shape VC  ·  "aún" · 3 letters · shape VVC

Frequently Asked Questions

Is swapping "aj" for "aún" ever safe?
No - they are not even the same part of speech. "aj" is a noun and "aún" an adverb, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "aj" vs "aún" - which ranks higher?
"aún" is the more common of the two: it sits at frequency rank #240 in our Spanish list, against #21,891 for "aj". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "aj" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "aún" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #251,768 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "aj" and "aún" also get mixed up with nearby pairs, the highest-scored neighbour is "aj vs atl". Nearby pair

Confusion rank #251,768 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