Which to use
“fast” is an adverb and “foste” is a verb - they look or sound alike but fill different roles in a sentence.
- #8,052
- “fast” frequency rank
- #11,469
- “foste” frequency rank
- 19521
- confusion score
Side-by-Side Comparison
| Feature | fast | foste |
|---|---|---|
| Definition | quase | segunda pessoa do singular do pretérito perfeito do indicativo do verbo ser |
Where the eye mixes fast and foste
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. fast runs 4 letters (CVCC) against foste's 5 (CVCCV) - the length gap alone is often enough to separate them once you know to check it.
Visual trap between fast and foste
These two trip readers on the page rather than in the ear: fast is /fast/ while foste is /ˈfos.ʧi/. 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 verb), which is usually the fastest check. Our composite confusion score for this pair is 19521, derived from the frequency rank of both members and their visual similarity.
fast is recorded at frequency rank #8,052, classified as anadv, pronounced /fast/. foste is at rank #11,469, tagged as averb, pronounced /ˈfos.ʧi/.
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 19521, this pair ranks #51,174 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fast vs foste
Shared letters: fst. Private to "fast": a. Private to "foste": eo.
"fast" · 4 letters · shape CVCC · "foste" · 5 letters · shape CVCCV
Known mistypes of this pair
Frequently Asked Questions
Do "fast" and "foste" mean the same thing in a sentence?
Which is more common, "fast" or "foste"?
Useful next steps
Eye-level mix-up between "fast" and "foste" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "fast" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "foste" - compare definitions side by side with the headword page. Word entry
- This pair ranks #51,174 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
- "fast" and "foste" also get mixed up with nearby pairs, the highest-scored neighbour is "fosco vs foste". 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 #51,174 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.