willfulvswillfullyWhat's the difference?

Quick tell: willful is a adjective, willfully is an adverb, so they fill different roles in a sentence.

Which to use

“willful” is an adjective and “willfully” is an adverb - they look or sound alike but fill different roles in a sentence.

#26,308
“willful” frequency rank
#26,660
“willfully” frequency rank
52968
confusion score

Side-by-Side Comparison

Feature willful willfully
Definition American standard spelling of wilful. US standard spelling of wilfully.

Letter map: willful vs willfully

Shared letters muted; letters that set willful and willfully apart highlighted. Shared run: 7.

7 ch
willful
9 ch
willfully

Grammar separator: willful vs willfully

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: willful is anadjective and willfullyanadverb. On the page they differ by 2 extra letter(s) - “willful” sits inside “willfully”. Our composite confusion score for this pair is 52968, derived from the frequency rank of both members and their visual similarity.

willful is recorded at frequency rank #26,308, classified as anadj. willfully is at rank #26,660, tagged as anadv.

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 52968, this pair ranks #152,736 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of willful vs willfully

Shared letters: filuw. Private to "willful": -. Private to "willfully": y.

"willful" · 7 letters · shape CVCCCVC  ·  "willfully" · 9 letters · shape CVCCCVCCV

Known mistypes of this pair

  • willfuliwllful · wilflul · willfful · willflu · willfull · willufl · wlilful · wwillful
  • willfullyiwllfully · wilflully · willffully · willfluly · willfullyy · willfuly · willfulyl · willuflly

Frequently Asked Questions

Is swapping "willful" for "willfully" ever safe?
No - they are not even the same part of speech. "willful" is an adjective and "willfully" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "willful" or "willfully"?
"willful" is the more common of the two: it sits at frequency rank #26,308 in our English list, against #26,660 for "willfully". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Done with this confusable. These links stay specific to "willful" and "willfully".

  • Full dictionary entry for "willful" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "willfully" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #152,736 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "willful" and "willfully" also get mixed up with nearby pairs, the highest-scored neighbour is "wilfully vs willfully". 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 #152,736 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