fluirvsfuiWhich spelling fits?

Which to use

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

#14,377
“fluir” frequency rank
#365
“fui” frequency rank
14742
confusion score

Side-by-Side Comparison

Feature fluir fui
Definition correr como os líquidos primeira pessoa do singular do pretérito perfeito simples do indicativo do verbo ir:

Where the eye mixes fluir and fui

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. fluir runs 5 letters (CCVVC) against fui's 3 (CVV) - the length gap alone is often enough to separate them once you know to check it.

5 ch
fluir
3 ch
fui

Why the eye confuses fluir with fui

A purely visual mix-up. fluir (/ˈflwiɾ/) and fui (/ˈfuj/) 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 2 letter(s) in length. Our composite confusion score for this pair is 14742, derived from the frequency rank of both members and their visual similarity.

fluir is recorded at frequency rank #14,377, classified as averb, pronounced /ˈflwiɾ/. fui is at rank #365, tagged as averb, pronounced /ˈfuj/.

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 14742, this pair ranks #57,260 of 75,631 scored Portuguese confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of fluir vs fui

Shared letters: fiu. Private to "fluir": lr. Private to "fui": -.

"fluir" · 5 letters · shape CCVVC  ·  "fui" · 3 letters · shape CVV

Known mistypes of this pair

  • fluir ← ffluir · fliur · flluir · fluirr · fluri · fulir · lfuir

Frequently Asked Questions

Is swapping "fluir" for "fui" ever safe?
No. They are said differently (/ˈflwiɾ/ versus /ˈfuj/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "fluir" or "fui"?
"fui" is the more common of the two: it sits at frequency rank #365 in our Portuguese list, against #14,377 for "fluir". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "fluir" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fui" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #57,260 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "fluir" and "fui" also get mixed up with nearby pairs, the highest-scored neighbour is "fleur vs fluir". 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 #57,260 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