successfulvssuccessfullyWhat's the difference?

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

Which to use

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

#1,238
“successful” frequency rank
#3,337
“successfully” frequency rank
4575
confusion score

Side-by-Side Comparison

Feature successful successfully
Definition Resulting in success; assuring or promoting success; accomplishing what was proposed; having the desired effect. In a successful manner; with success; without failing.

Where the spellings diverge

Shared letters are muted; the letters that actually set successful and successfully apart are highlighted. They share 10 letters in sequence, which is exactly why the eye skips the difference.

10 ch
successful
12 ch
successfully

Spelling & Dictionary Insight

successful and successfully form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by 2 extra letter(s) - “successful” sits inside “successfully” - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 4575, derived from the frequency rank of both members and their visual similarity.

successful is recorded at frequency rank #1,238, classified as anadj, pronounced /səkˈsɛs.fəl/. successfully is at rank #3,337, tagged as anadv, pronounced /səkˈsɛs.fə.li/.

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 4575, this pair ranks #518,447 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Frequency comparison

successful#1,238
successfully#3,337

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "successful" and "successfully" be used interchangeably?
No, "successful" and "successfully" have distinct meanings and cannot be swapped without changing the meaning of a sentence. Understanding the specific definition and context for each word is essential for correct usage.

Remembering successful vs successfully

The fastest way to pick the right one every time.

  • Check the role first: if you need an adjective, it's “successful”; for an adverb, it's “successfully”.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “successful” 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