Which to use
“secondary” is an adjective and “secondly” is an adverb - they look or sound alike but fill different roles in a sentence.
- #2,861
- “secondary” frequency rank
- #8,981
- “secondly” frequency rank
- 11842
- confusion score
Side-by-Side Comparison
| Feature | secondary | secondly |
|---|---|---|
| Definition | Next in order to the first or primary; of second place in origin, rank, etc. | In the second place. |
Where the eye mixes secondary and secondly
Muted = shared; highlighted = the visual trap. They share 7 letters in sequence.
Why the eye confuses secondary with secondly
These two trip readers on the page rather than in the ear: secondary is /ˈsɛkənd(ə)ɹɪ/ while secondly is /ˈsɛk.(ə)ndli/. 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 11842, derived from the frequency rank of both members and their visual similarity.
secondary is recorded at frequency rank #2,861, classified as anadj, pronounced /ˈsɛkənd(ə)ɹɪ/. secondly is at rank #8,981, tagged as anadv, pronounced /ˈsɛk.(ə)ndli/.
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 11842, this pair ranks #484,845 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of secondary vs secondly
Shared letters: cdenosy. Private to "secondary": ar. Private to "secondly": l.
"secondary" · 9 letters · shape CVCVCCVCV · "secondly" · 8 letters · shape CVCVCCCV
Known mistypes of this pair
Frequently Asked Questions
Can "secondary" and "secondly" be used interchangeably?
Frequency check: "secondary" vs "secondly" - which ranks higher?
What to do next
Eye-level mix-up between "secondary" and "secondly" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "secondary" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "secondly" - compare definitions side by side with the headword page. Word entry
- This pair ranks #484,845 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "secondary" and "secondly" also get mixed up with nearby pairs, the highest-scored neighbour is "seconded vs secondly". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #484,845 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.