atovsaufWhat's the difference?

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

Which to use

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

#1,326
“ato” frequency rank
#42,318
“auf” frequency rank
43644
confusion score

Side-by-Side Comparison

Feature ato auf
Definition processo de fazer algo; manifestação real e tangível aberto

Where the eye mixes ato and auf

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence. ato (VCV) and auf (VVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.

3 ch
ato
3 ch
auf

Visual trap between ato and auf

These two trip readers on the page rather than in the ear: ato is /ˈato/ ou /ˈatu/_(plural:) /ˈatos/, /ˈatus/ ou /ˈatuʃ/ while auf is /aʊ̯f/. 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 (noun vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 43644, derived from the frequency rank of both members and their visual similarity.

ato is recorded at frequency rank #1,326, classified as anoun, pronounced /ˈato/ ou /ˈatu/_(plural:) /ˈatos/, /ˈatus/ ou /ˈatuʃ/. auf is at rank #42,318, tagged as anadv, 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 43644, this pair ranks #21,987 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of ato vs auf

Shared letters: a. Private to "ato": ot. Private to "auf": fu.

"ato" · 3 letters · shape VCV  ·  "auf" · 3 letters · shape VVC

Frequently Asked Questions

Is swapping "ato" for "auf" ever safe?
No - they are not even the same part of speech. "ato" is a noun and "auf" an adverb, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "ato" vs "auf" - which ranks higher?
"ato" is the more common of the two: it sits at frequency rank #1,326 in our Portuguese list, against #42,318 for "auf". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

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 "ato" 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 #21,987 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "ato" and "auf" also get mixed up with nearby pairs, the highest-scored neighbour is "acs vs auf". Nearby pair

Confusion rank #21,987 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list