badly vs bly, What's the Difference?

Which to use

“badly” is an adverb and “bly” is a noun - they look or sound alike but fill different roles in a sentence.

#3,351
“badly” frequency rank: #46,343
“bly” frequency rank: 49694
confusion score

Side-by-Side Comparison

Feature	badly	bly
Definition	In a bad manner.	Likeness; resemblance; look aspect; species; character.

Where the spellings diverge

Shared letters are muted; the letters that actually set badly and bly apart are highlighted. They share 3 letters in sequence, which is exactly why the eye skips the difference.

5 ch

badly

3 ch

bly

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: badly is /ˈbæd.li/ while bly is /blaɪ/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 letter(s) in length, and the parts of speech differ too (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 49694, derived from the frequency rank of both members and their visual similarity.

badly is recorded at frequency rank #3,351, classified as anadv, pronounced /ˈbæd.li/. bly is at rank #46,343, tagged as anoun, pronounced /blaɪ/.

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 49694, this pair ranks #181,210 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of badly vs bly

Shared letters: bly. Private to "badly": ad. Private to "bly": -.

"badly" · 5 letters · shape CVCCV · "bly" · 3 letters · shape CCV

Known mistypes of this pair

badly ← abdly · baddly · badlly · badlyy · badyl · bbadly · bdaly

Frequency comparison

badly#3,351

bly#46,343

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "badly" and "bly" be used interchangeably?

No - they are not even the same part of speech. "badly" is an adverb and "bly" a noun, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "badly" or "bly"?

"badly" is the more common of the two: it sits at frequency rank #3,351 in our English list, against #46,343 for "bly". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Remembering badly vs bly

The fastest way to pick the right one every time.

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