Which to use
“thorough” is an adjective and “thoroughly” is an adverb - they look or sound alike but fill different roles in a sentence.
- #7,512
- “thorough” frequency rank
- #6,193
- “thoroughly” frequency rank
- 13705
- confusion score
Side-by-Side Comparison
| Feature | thorough | thoroughly |
|---|---|---|
| Definition | Painstaking and careful not to miss or omit any detail. | In a thorough or complete manner. |
Where the eye mixes thorough and thoroughly
Muted = shared; highlighted = the visual trap. They share 8 letters in sequence.
Spelling & Dictionary Insight
These two trip readers on the page rather than in the ear: thorough is /ˈθʌɹə/ while thoroughly is /ˈθʌɹ.ə.li/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “thorough” sits inside “thoroughly”, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 13705, derived from the frequency rank of both members and their visual similarity.
thorough is recorded at frequency rank #7,512, classified as anadj, pronounced /ˈθʌɹə/. thoroughly is at rank #6,193, tagged as anadv, pronounced /ˈθʌɹ.ə.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 13705, this pair ranks #474,277 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of thorough vs thoroughly
Shared letters: ghortu. Private to "thorough": -. Private to "thoroughly": ly.
"thorough" · 8 letters · shape CCVCVVCC · "thoroughly" · 10 letters · shape CCVCVVCCCV
Known mistypes of this pair
- thorough ← htorough · thhorough · thoorugh · thoroguh · thorouggh · thoroughh · thorouhg · thorrough
- thoroughly ← htoroughly · thhoroughly · thoorughly · thoroguhly · thorougghly · thoroughhly · thoroughlly · thoroughlyy