Which to use
“fax” is a noun and “foi” is a verb - they look or sound alike but fill different roles in a sentence.
- #14,370
- “fax” frequency rank
- #26
- “foi” frequency rank
- 14396
- confusion score
Side-by-Side Comparison
| Feature | fax | foi |
|---|---|---|
| Definition | aparelho transmissor e receptor de documentos em fac-símile | terceira pessoa do singular do pretérito perfeito do indicativo do verbo ser |
Where the eye mixes fax and foi
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between fax and foi
These two trip readers on the page rather than in the ear: fax is /ˈfaks/ while foi is /ˈfoj/. 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 verb), which is usually the fastest check. Our composite confusion score for this pair is 14396, derived from the frequency rank of both members and their visual similarity.
fax is recorded at frequency rank #14,370, classified as anoun, pronounced /ˈfaks/. foi is at rank #26, tagged as averb, pronounced /ˈfoj/.
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 14396, this pair ranks #57,697 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of fax vs foi
Shared letters: f. Private to "fax": ax. Private to "foi": io.
"fax" · 3 letters · shape CVC · "foi" · 3 letters · shape CVV
Frequently Asked Questions
Can "fax" and "foi" be used interchangeably?
Frequency check: "fax" vs "foi" - which ranks higher?
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 "fax" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "foi" - compare definitions side by side with the headword page. Word entry
- This pair ranks #57,697 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
- "fax" and "foi" also get mixed up with nearby pairs, the highest-scored neighbour is "fava vs fax". Nearby pair
Confusion rank #57,697 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.