cheiovscioWhich spelling fits?

Quick tell: cheio is a adjective, cio is a noun, so they fill different roles in a sentence.

Which to use

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

#1,424
“cheio” frequency rank
#22,564
“cio” frequency rank
23988
confusion score

Side-by-Side Comparison

Feature cheio cio
Definition completamente preenchido; que contém o máximo que pode conter período de maior apetite sexual e fertilidade de certos animais

Where the eye mixes cheio and cio

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

5 ch
cheio
3 ch
cio

Why the eye confuses cheio with cio

These two trip readers on the page rather than in the ear: cheio is /ˈʃɐj.u/ while cio is /ˈsi.u/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 letter(s) in length, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 23988, derived from the frequency rank of both members and their visual similarity.

cheio is recorded at frequency rank #1,424, classified as anadj, pronounced /ˈʃɐj.u/. cio is at rank #22,564, tagged as anoun, pronounced /ˈsi.u/.

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 23988, this pair ranks #45,735 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of cheio vs cio

Shared letters: cio. Private to "cheio": eh. Private to "cio": -.

"cheio" · 5 letters · shape CCVVV  ·  "cio" · 3 letters · shape CVV

Known mistypes of this pair

  • cheioccheio · cehio · cheoi · chheio · chieo · hceio

Frequently Asked Questions

Can "cheio" and "cio" be used interchangeably?
No - they are not even the same part of speech. "cheio" is an adjective and "cio" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary Portuguese text, does "cheio" or "cio" show up more?
"cheio" is the more common of the two: it sits at frequency rank #1,424 in our Portuguese list, against #22,564 for "cio". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

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

  • Full dictionary entry for "cheio" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "cio" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #45,735 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "cheio" and "cio" also get mixed up with nearby pairs, the highest-scored neighbour is "ciao vs cio". 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 #45,735 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