Which to use
“fills” is a verb and “filly” is a noun - they look or sound alike but fill different roles in a sentence.
- #11,032
- “fills” frequency rank
- #23,832
- “filly” frequency rank
- 34864
- confusion score
Side-by-Side Comparison
| Feature | fills | filly |
|---|---|---|
| Definition | third-person singular simple present indicative of fill | A young female horse. |
Where the eye mixes fills and filly
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Why the eye confuses fills with filly
These two trip readers on the page rather than in the ear: fills is /fɪlz/ while filly is /ˈfɪli/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - s in “fills” becomes y in “filly”, and the parts of speech differ too (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 34864, derived from the frequency rank of both members and their visual similarity.
fills is recorded at frequency rank #11,032, classified as averb, pronounced /fɪlz/. filly is at rank #23,832, tagged as anoun, pronounced /ˈfɪli/.
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 34864, this pair ranks #316,978 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fills vs filly
Shared letters: fil. Private to "fills": s. Private to "filly": y.
"fills" · 5 letters · shape CVCCC · "filly" · 5 letters · shape CVCCV
Known mistypes of this pair
Frequently Asked Questions
Can "fills" and "filly" be used interchangeably?
Which is more common, "fills" or "filly"?
After this comparison
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "fills" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "filly" - compare definitions side by side with the headword page. Word entry
- This pair ranks #316,978 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "fills" and "filly" also get mixed up with nearby pairs, the highest-scored neighbour is "feely vs filly". 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 #316,978 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.