dreadfulvsdreadfullyWhich spelling fits?

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

Which to use

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

#11,882
“dreadful” frequency rank
#41,600
“dreadfully” frequency rank
53482
confusion score

Side-by-Side Comparison

Feature dreadful dreadfully
Definition Full of something causing dread, whether In a dreadful manner; terribly.

Where the eye mixes dreadful and dreadfully

Muted = shared; highlighted = the visual trap. They share 8 letters in sequence.

8 ch
dreadful
10 ch
dreadfully

Visual trap between dreadful and dreadfully

These two trip readers on the page rather than in the ear: dreadful is /ˈdɹɛd.fl̩/ while dreadfully is /ˈdɹɛd.fʊl.i/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “dreadful” sits inside “dreadfully”, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 53482, derived from the frequency rank of both members and their visual similarity.

dreadful is recorded at frequency rank #11,882, classified as anadj, pronounced /ˈdɹɛd.fl̩/. dreadfully is at rank #41,600, tagged as anadv, pronounced /ˈdɹɛd.fʊl.i/.

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 53482, this pair ranks #148,590 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of dreadful vs dreadfully

Shared letters: adeflru. Private to "dreadful": -. Private to "dreadfully": y.

"dreadful" · 8 letters · shape CCVVCCVC  ·  "dreadfully" · 10 letters · shape CCVVCCVCCV

Known mistypes of this pair

  • dreadfulddreadful · deradful · draedful · dreaddful · dreadfful · dreadflu · dreadfull · dreadufl
  • dreadfullyddreadfully · deradfully · draedfully · dreaddfully · dreadffully · dreadfluly · dreadfullyy · dreadfuly

Frequently Asked Questions

Is swapping "dreadful" for "dreadfully" ever safe?
No - they are not even the same part of speech. "dreadful" is an adjective and "dreadfully" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "dreadful" or "dreadfully"?
"dreadful" is the more common of the two: it sits at frequency rank #11,882 in our English list, against #41,600 for "dreadfully". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "dreadful" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "dreadfully" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #148,590 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • 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 #148,590 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