caisvscioWhich spelling fits?

Which to use

“cais” and “cio” are a confusable Portuguese pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#10,845
“cais” frequency rank
#22,564
“cio” frequency rank
33409
confusion score

Side-by-Side Comparison

Feature cais cio
Definition lugar à beira-mar, na margem do rio, nas estações de caminho-de-ferro ou do metropolitano apropriado para o embarque e desembarque de pessoas ou mercadorias período de maior apetite sexual e fertilidade de certos animais

Where the eye mixes cais and cio

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

4 ch
cais
3 ch
cio

Visual trap between cais and cio

A purely visual mix-up. cais (/ˈkajʃ/) and cio (/ˈsi.u/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 33409, derived from the frequency rank of both members and their visual similarity.

cais is recorded at frequency rank #10,845, classified as anoun, pronounced /ˈkajʃ/. 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 33409, this pair ranks #34,123 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of cais vs cio

Shared letters: ci. Private to "cais": as. Private to "cio": o.

"cais" · 4 letters · shape CVVC  ·  "cio" · 3 letters · shape CVV

Known mistypes of this pair

  • caisacis · caiss · casi · ccais · cias

Frequently Asked Questions

Do "cais" and "cio" mean the same thing in a sentence?
No. They are said differently (/ˈkajʃ/ versus /ˈsi.u/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "cais" or "cio"?
"cais" is the more common of the two: it sits at frequency rank #10,845 in our Portuguese list, against #22,564 for "cio". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

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 "cais" 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 #34,123 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "cais" 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 #34,123 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