an vs ato, What's the Difference?

Which to use

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

#2,817
“an” frequency rank: #1,326
“ato” frequency rank: 4143
confusion score

Side-by-Side Comparison

Feature	an	ato
Definition	ligado, aceso:	processo de fazer algo; manifestação real e tangível

Where the eye mixes an and ato

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

2 ch

3 ch

ato

Why the eye confuses an with ato

These two trip readers on the page rather than in the ear: an is /an/ while ato is /ˈato/ ou /ˈatu/_(plural:) /ˈatos/, /ˈatus/ ou /ˈatuʃ/. 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 (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 4143, derived from the frequency rank of both members and their visual similarity.

an is recorded at frequency rank #2,817, classified as anadv, pronounced /an/. ato is at rank #1,326, tagged as anoun, pronounced /ˈato/ ou /ˈatu/_(plural:) /ˈatos/, /ˈatus/ ou /ˈatuʃ/.

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 4143, this pair ranks #70,858 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of an vs ato

Shared letters: a. Private to "an": n. Private to "ato": ot.

"an" · 2 letters · shape VC · "ato" · 3 letters · shape VCV

Frequently Asked Questions

Can "an" and "ato" be used interchangeably?

No - they are not even the same part of speech. "an" is an adverb and "ato" a noun, so a sentence built for one is usually ungrammatical with the other.

In ordinary Portuguese text, does "an" or "ato" show up more?

"ato" is the more common of the two: it sits at frequency rank #1,326 in our Portuguese list, against #2,817 for "an". 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 "an" and "ato" is sorted above. Next: full entries or other pairs that share a letter shape.

Full dictionary entry for "an" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "ato" - compare definitions side by side with the headword page. Word entry
This pair ranks #70,858 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
"an" and "ato" also get mixed up with nearby pairs, the highest-scored neighbour is "acs vs an". Nearby pair

Confusion rank #70,858 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.