CairovscaisWhat's the difference?

Which to use

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

#9,303
“Cairo” frequency rank
#10,845
“cais” frequency rank
20148
confusion score

Side-by-Side Comparison

Feature Cairo cais
Definition capital do Egito, país no qual é a maior cidade, posto que também ocupa no chamado mundo árabe 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

Where the eye mixes Cairo and cais

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

5 ch
Cairo
4 ch
cais

Why the eye confuses Cairo with cais

A purely visual mix-up. Cairo (/ˈkaj.ɾu/) and cais (/ˈkajʃ/) 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 20148, derived from the frequency rank of both members and their visual similarity.

Cairo is recorded at frequency rank #9,303, classified as anoun, pronounced /ˈkaj.ɾu/. cais is at rank #10,845, tagged as anoun, pronounced /ˈkajʃ/.

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 20148, this pair ranks #50,443 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of Cairo vs cais

Shared letters: aci. Private to "Cairo": or. Private to "cais": s.

"Cairo" · 5 letters · shape CVVCV  ·  "cais" · 4 letters · shape CVVC

Known mistypes of this pair

  • Cairoaciro · caior · cairro · cario · ccairo · ciaro
  • caisacis · caiss · casi · ccais · cias

Frequently Asked Questions

Is swapping "Cairo" for "cais" ever safe?
No. They are said differently (/ˈkaj.ɾu/ versus /ˈkajʃ/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "Cairo" vs "cais" - which ranks higher?
"Cairo" is the more common of the two: it sits at frequency rank #9,303 in our Portuguese list, against #10,845 for "cais". 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 "Cairo" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "cais" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #50,443 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "Cairo" and "cais" also get mixed up with nearby pairs, the highest-scored neighbour is "Cairo vs ciao". 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 #50,443 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