unduevsundulyWhat's the difference?

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

Which to use

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

#20,003
“undue” frequency rank
#29,875
“unduly” frequency rank
49878
confusion score

Side-by-Side Comparison

Feature undue unduly
Definition Excessive; going beyond that what is natural or sufficient. Undeservedly; in a way that is not warranted.

Where the spellings diverge

Shared letters are muted; the letters that actually set undue and unduly apart are highlighted. They share 4 letters in sequence, which is exactly why the eye skips the difference.

5 ch
undue
6 ch
unduly

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: undue is /ʌnˈdjuː/ while unduly is /ʌnˈdjuːli/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 49878, derived from the frequency rank of both members and their visual similarity.

undue is recorded at frequency rank #20,003, classified as anadj, pronounced /ʌnˈdjuː/. unduly is at rank #29,875, tagged as anadv, pronounced /ʌnˈdjuːli/.

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 49878, this pair ranks #179,446 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of undue vs unduly

Shared letters: dnu. Private to "undue": e. Private to "unduly": ly.

"undue" · 5 letters · shape VCCVV  ·  "unduly" · 6 letters · shape VCCVCV

Known mistypes of this pair

  • unduenudue · udnue · unddue · undeu · unndue · unude
  • undulynuduly · udnuly · undduly · undluy · undully · undulyy · unduyl · unnduly

Frequency comparison

undue#20,003
unduly#29,875

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "undue" and "unduly" be used interchangeably?
No - they are not even the same part of speech. "undue" is an adjective and "unduly" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "undue" or "unduly"?
"undue" is the more common of the two: it sits at frequency rank #20,003 in our English list, against #29,875 for "unduly". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Remembering undue vs unduly

The fastest way to pick the right one every time.

  • Check the role first: if you need an adjective, it's “undue”; for an adverb, it's “unduly”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “undue” 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 FrequencyWords open word-frequency list