fillingvsfoulingConfusable pair

Which to use

“filling” and “fouling” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#5,221
“filling” frequency rank
#32,811
“fouling” frequency rank
38032
confusion score

Side-by-Side Comparison

Feature filling fouling
Definition present participle and gerund of fill present participle and gerund of foul

Where the eye mixes filling and fouling

Muted = shared; highlighted = the visual trap. They share 5 letters in sequence.

7 ch
filling
7 ch
fouling

Why the eye confuses filling with fouling

A purely visual mix-up. filling (/ˈfɪlɪŋ/) and fouling (/ˈfaʊlɪŋ/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 38032, derived from the frequency rank of both members and their visual similarity.

filling is recorded at frequency rank #5,221, classified as averb, pronounced /ˈfɪlɪŋ/. fouling is at rank #32,811, tagged as averb, pronounced /ˈfaʊlɪŋ/.

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 38032, this pair ranks #289,412 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of filling vs fouling

Shared letters: fgiln. Private to "filling": -. Private to "fouling": ou.

"filling" · 7 letters · shape CVCCVCC  ·  "fouling" · 7 letters · shape CVVCVCC

Known mistypes of this pair

  • fillingffilling · fililng · fillign · fillingg · fillinng · fillnig · fliling · iflling
  • foulingffouling · foluing · fouilng · foulign · foulingg · foulinng · foulling · foulnig

Frequently Asked Questions

Can "filling" and "fouling" be used interchangeably?
No. They are said differently (/ˈfɪlɪŋ/ versus /ˈfaʊlɪŋ/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "filling" vs "fouling" - which ranks higher?
"filling" is the more common of the two: it sits at frequency rank #5,221 in our English list, against #32,811 for "fouling". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

  • Full dictionary entry for "filling" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fouling" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #289,412 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "filling" and "fouling" also get mixed up with nearby pairs, the highest-scored neighbour is "fondling vs fouling". 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 #289,412 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