Which to use
“improper” is an adjective and “improperly” is an adverb - they look or sound alike but fill different roles in a sentence.
- #13,366
- “improper” frequency rank
- #18,346
- “improperly” frequency rank
- 31712
- confusion score
Side-by-Side Comparison
| Feature | improper | improperly |
|---|---|---|
| Definition | Unsuitable to needs or circumstances; inappropriate; inapt. | In an improper manner; not properly. |
Where the eye mixes improper and improperly
Muted = shared; highlighted = the visual trap. They share 8 letters in sequence.
Look-alike desk: improper vs improperly
These two trip readers on the page rather than in the ear: improper is /ɪmˈpɹɒp.ə/ while improperly is /ɪmˈpɹɑ.pɚ.li/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “improper” sits inside “improperly”, and the parts of speech differ too (adjective vs adverb), which is usually the fastest check. Our composite confusion score for this pair is 31712, derived from the frequency rank of both members and their visual similarity.
improper is recorded at frequency rank #13,366, classified as anadj, pronounced /ɪmˈpɹɒp.ə/. improperly is at rank #18,346, tagged as anadv, pronounced /ɪmˈpɹɑ.pɚ.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 31712, this pair ranks #343,864 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of improper vs improperly
Shared letters: eimopr. Private to "improper": -. Private to "improperly": ly.
"improper" · 8 letters · shape VCCCVCVC · "improperly" · 10 letters · shape VCCCVCVCCV
Known mistypes of this pair
- improper ← immproper · imporper · impproper · improepr · improperr · impropper · impropre · imprpoer
- improperly ← immproperly · imporperly · impproperly · improeprly · impropelry · improperlly · improperlyy · improperrly
Frequently Asked Questions
Do "improper" and "improperly" mean the same thing in a sentence?
Which is more common, "improper" or "improperly"?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "improper" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "improperly" - compare definitions side by side with the headword page. Word entry
- This pair ranks #343,864 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "improper" and "improperly" also get mixed up with nearby pairs, the highest-scored neighbour is "improper vs improved". 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 #343,864 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.