undoubtedvsundoubtedlyWhat's the difference?

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

Which to use

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

#46,834
“undoubted” frequency rank
#8,621
“undoubtedly” frequency rank
55455
confusion score

Side-by-Side Comparison

Feature undoubted undoubtedly
Definition Without doubt; without question; certain. Without doubt; definitely.

Where the spellings diverge

Shared letters are muted; the letters that actually set undoubted and undoubtedly apart are highlighted. They share 9 letters in sequence, which is exactly why the eye skips the difference.

9 ch
undoubted
11 ch
undoubtedly

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: undoubted is /ʌnˈdaʊtɪd/ while undoubtedly is /ʌnˈdaʊtɪdli/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “undoubted” sits inside “undoubtedly”, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 55455, derived from the frequency rank of both members and their visual similarity.

undoubted is recorded at frequency rank #46,834, classified as anadj, pronounced /ʌnˈdaʊtɪd/. undoubtedly is at rank #8,621, tagged as anadv, pronounced /ʌnˈdaʊtɪdli/.

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 55455, this pair ranks #133,507 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of undoubted vs undoubtedly

Shared letters: bdenotu. Private to "undoubted": -. Private to "undoubtedly": ly.

"undoubted" · 9 letters · shape VCCVVCCVC  ·  "undoubtedly" · 11 letters · shape VCCVVCCVCCV

Known mistypes of this pair

  • undoubtednudoubted · udnoubted · unddoubted · undobuted · undoubbted · undoubetd · undoubtde · undoubtedd
  • undoubtedlynudoubtedly · udnoubtedly · unddoubtedly · undobutedly · undoubbtedly · undoubetdly · undoubtdely · undoubteddly

Frequency comparison

undoubted#46,834
undoubtedly#8,621

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "undoubted" and "undoubtedly" be used interchangeably?
No - they are not even the same part of speech. "undoubted" is an adjective and "undoubtedly" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "undoubted" or "undoubtedly"?
"undoubtedly" is the more common of the two: it sits at frequency rank #8,621 in our English list, against #46,834 for "undoubted". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Remembering undoubted vs undoubtedly

The fastest way to pick the right one every time.

  • Check the role first: if you need an adjective, it's “undoubted”; for an adverb, it's “undoubtedly”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “undoubted” entry
  • Browse more pairs most likely to be confused. Most confusable

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list