fastvsfutConfusable pair

Quick tell: fast is a adjective, fut is an intj, so they fill different roles in a sentence.

Which to use

“fast” is an adjective and “fut” is an intj - they look or sound alike but fill different roles in a sentence.

#767
“fast” frequency rank
#44,798
“fut” frequency rank
45565
confusion score

Side-by-Side Comparison

Feature fast fut
Definition Firmly or securely fixed in place; stable. Alternative form of 'sfoot.

Letter map: fast vs fut

Shared letters muted; letters that set fast and fut apart highlighted. Shared run: 2.

4 ch
fast
3 ch
fut

Role in the sentence - fast and fut

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: fast is anadjective and futanintj. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 45565, derived from the frequency rank of both members and their visual similarity.

fast is recorded at frequency rank #767, classified as anadj, pronounced /fɑːst/. fut is at rank #44,798, tagged as anintj.

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 45565, this pair ranks #220,063 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of fast vs fut

Shared letters: ft. Private to "fast": as. Private to "fut": u.

"fast" · 4 letters · shape CVCC  ·  "fut" · 3 letters · shape CVC

Known mistypes of this pair

  • fastafst · fasst · fastt · ffast · fsat

Frequently Asked Questions

Can "fast" and "fut" be used interchangeably?
No - they are not even the same part of speech. "fast" is an adjective and "fut" an intj, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "fast" or "fut" show up more?
"fast" is the more common of the two: it sits at frequency rank #767 in our English list, against #44,798 for "fut". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Pair "fast" vs "fut" is on the table, pick a follow-up below.

  • Full dictionary entry for "fast" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fut" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #220,063 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "fast" and "fut" also get mixed up with nearby pairs, the highest-scored neighbour is "foh vs fut". 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 #220,063 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list