fiftyvsfilthyConfusable pair

Quick tell: fifty is a num, filthy is an adjective, so they fill different roles in a sentence.

Which to use

“fifty” is a num and “filthy” is an adjective - they look or sound alike but fill different roles in a sentence.

#4,376
“fifty” frequency rank
#9,608
“filthy” frequency rank
13984
confusion score

Side-by-Side Comparison

Feature fifty filthy
Definition The cardinal number occurring after forty-nine and before fifty-one. Covered with filth; very dirty.

Where the eye mixes fifty and filthy

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.

5 ch
fifty
6 ch
filthy

Look-alike desk: fifty vs filthy

These two trip readers on the page rather than in the ear: fifty is /ˈfɪfti/ while filthy is /ˈfɪlθi/. 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 (num vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 13984, derived from the frequency rank of both members and their visual similarity.

fifty is recorded at frequency rank #4,376, classified as anum, pronounced /ˈfɪfti/. filthy is at rank #9,608, tagged as anadj, pronounced /ˈfɪlθi/.

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 13984, this pair ranks #472,730 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of fifty vs filthy

Shared letters: fity. Private to "fifty": -. Private to "filthy": hl.

"fifty" · 5 letters · shape CVCCV  ·  "filthy" · 6 letters · shape CVCCCV

Known mistypes of this pair

  • fiftyffifty · ffity · fiffty · fiftty · fiftyy · fifyt · fitfy · iffty
  • filthyffilthy · filhty · fillthy · filthhy · filthyy · filtthy · filtyh · fitlhy

Frequently Asked Questions

Can "fifty" and "filthy" be used interchangeably?
No - they are not even the same part of speech. "fifty" is a num and "filthy" an adjective, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "fifty" or "filthy"?
"fifty" is the more common of the two: it sits at frequency rank #4,376 in our English list, against #9,608 for "filthy". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "fifty" and "filthy" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "fifty" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "filthy" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #472,730 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "fifty" and "filthy" also get mixed up with nearby pairs, the highest-scored neighbour is "filthy vs frothy". 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 #472,730 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