af vs auf, What's the Difference?

Which to use

“af” is an adjective and “auf” is a preposition - they look or sound alike but fill different roles in a sentence.

#20,246
“af” frequency rank: #35,364
“auf” frequency rank: 55610
confusion score

Side-by-Side Comparison

Feature	af	auf
Definition	Enfermo.	Arriba de, sobre, en.

Where the eye mixes af and auf

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

2 ch

3 ch

auf

Why the eye confuses af with auf

These two trip readers on the page rather than in the ear: af is /af/ while auf is [aʊ̯f]. 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 preposition), which is usually the fastest check. Our composite confusion score for this pair is 55610, derived from the frequency rank of both members and their visual similarity.

af is recorded at frequency rank #20,246, classified as anadj, pronounced /af/. auf is at rank #35,364, tagged as aprep, pronounced [aʊ̯f].

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 55610, this pair ranks #78,125 of 323,831 scored Spanish confusable pairs - among the most confusable pairs.

Orthographic DNA of af vs auf

Shared letters: af. Private to "af": -. Private to "auf": u.

"af" · 2 letters · shape VC · "auf" · 3 letters · shape VVC

Frequently Asked Questions

Is swapping "af" for "auf" ever safe?

No - they are not even the same part of speech. "af" is an adjective and "auf" a preposition, so a sentence built for one is usually ungrammatical with the other.

In ordinary Spanish text, does "af" or "auf" show up more?

"af" is the more common of the two: it sits at frequency rank #20,246 in our Spanish list, against #35,364 for "auf". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

Full dictionary entry for "af" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "auf" - compare definitions side by side with the headword page. Word entry
This pair ranks #78,125 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
"af" and "auf" also get mixed up with nearby pairs, the highest-scored neighbour is "atl vs auf". Nearby pair

Confusion rank #78,125 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.