fluvsfouWhat's the difference?

Quick tell: flu is a noun, fou is an adjective, so they fill different roles in a sentence.

Which to use

“flu” is a noun and “fou” is an adjective - they look or sound alike but fill different roles in a sentence.

#7,564
“flu” frequency rank
#48,244
“fou” frequency rank
55808
confusion score

Side-by-Side Comparison

Feature flu fou
Definition Influenza. Drunk.

Letter map: flu vs fou

Shared letters muted; letters that set flu and fou apart highlighted. Shared run: 2.

3 ch
flu
3 ch
fou

Spelling & Dictionary Insight

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: flu is anoun and fouanadjective. On the page they differ by a single letter - l in “flu” becomes o in “fou”. Our composite confusion score for this pair is 55808, derived from the frequency rank of both members and their visual similarity.

flu is recorded at frequency rank #7,564, classified as anoun, pronounced /fluː/. fou is at rank #48,244, tagged as anadj.

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 55808, this pair ranks #130,794 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of flu vs fou

Shared letters: fu. Private to "flu": l. Private to "fou": o.

"flu" · 3 letters · shape CCV  ·  "fou" · 3 letters · shape CVV

Frequently Asked Questions

Can "flu" and "fou" be used interchangeably?
No - they are not even the same part of speech. "flu" is a noun and "fou" an adjective, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "flu" or "fou"?
"flu" is the more common of the two: it sits at frequency rank #7,564 in our English list, against #48,244 for "fou". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

You've compared "flu" and "fou". Here's where to go from here.

  • Full dictionary entry for "flu" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fou" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #130,794 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "flu" and "fou" also get mixed up with nearby pairs, the highest-scored neighbour is "FOMO vs fou". Nearby pair

PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list