seriousvsseriouslyWhat's the difference?

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

Which to use

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

#836
“serious” frequency rank
#1,235
“seriously” frequency rank
2071
confusion score

Side-by-Side Comparison

Feature serious seriously
Definition Without humor or expression of happiness; grave in manner or disposition. In a serious or literal manner.

Where the eye mixes serious and seriously

Muted = shared; highlighted = the visual trap. They share 7 letters in sequence.

7 ch
serious
9 ch
seriously

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: serious is /ˈsɪə̯.ɹi.əs/ while seriously is /ˈsɪə.ɹi.əs.li/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “serious” sits inside “seriously”, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 2071, derived from the frequency rank of both members and their visual similarity.

serious is recorded at frequency rank #836, classified as anadj, pronounced /ˈsɪə̯.ɹi.əs/. seriously is at rank #1,235, tagged as anadv, pronounced /ˈsɪə.ɹi.əs.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 2071, this pair ranks #525,934 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of serious vs seriously

Shared letters: eiorsu. Private to "serious": -. Private to "seriously": ly.

"serious" · 7 letters · shape CVCVVVC  ·  "seriously" · 9 letters · shape CVCVVVCCV

Known mistypes of this pair

  • seriousesrious · seirous · seriosu · seriouss · seriuos · seroius · serrious · sreious
  • seriouslyesriously · seirously · seriosuly · serioulsy · seriouslly · seriouslyy · serioussly · seriousyl

Frequently Asked Questions

Can "serious" and "seriously" be used interchangeably?
No - they are not even the same part of speech. "serious" is an adjective and "seriously" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "serious" or "seriously"?
"serious" is the more common of the two: it sits at frequency rank #836 in our English list, against #1,235 for "seriously". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

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

Source: FrequencyWords open word-frequency list