soundlyvsSundayTell them apart

Quick tell: soundly is a adverb, Sunday is a noun, so they fill different roles in a sentence.

Which to use

“soundly” is an adverb and “Sunday” is a noun - they look or sound alike but fill different roles in a sentence.

#30,238
“soundly” frequency rank
#1,287
“Sunday” frequency rank
31525
confusion score

Side-by-Side Comparison

Feature soundly Sunday
Definition In a thorough manner; in manner free of defect or deficiency. The first day of the week in many religious traditions, and the seventh day of the week in systems using the ISO 8601 standard; the Christian Sabbath; the Lord's Day; it follows Saturday and precedes Monday.

Where the eye mixes soundly and Sunday

Muted = shared; highlighted = the visual trap. They share 5 letters in sequence.

7 ch
soundly
6 ch
Sunday

Why the eye confuses soundly with Sunday

These two trip readers on the page rather than in the ear: soundly is /ˈsaʊnd.lɪ/ while Sunday is /ˈsʌn.deɪ/. 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 (adverb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 31525, derived from the frequency rank of both members and their visual similarity.

soundly is recorded at frequency rank #30,238, classified as anadv, pronounced /ˈsaʊnd.lɪ/. Sunday is at rank #1,287, tagged as anoun, pronounced /ˈsʌn.deɪ/.

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 31525, this pair ranks #345,374 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of soundly vs Sunday

Shared letters: dnsuy. Private to "soundly": lo. Private to "Sunday": a.

"soundly" · 7 letters · shape CVVCCCV  ·  "Sunday" · 6 letters · shape CVCCVV

Known mistypes of this pair

  • soundlyosundly · sonudly · soudnly · sounddly · soundlly · soundlyy · soundyl · sounldy
  • Sundaysnuday · ssunday · sudnay · sunady · sundayy · sundday · sundya · sunnday

Frequently Asked Questions

Is swapping "soundly" for "Sunday" ever safe?
No - they are not even the same part of speech. "soundly" is an adverb and "Sunday" a noun, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "soundly" vs "Sunday" - which ranks higher?
"Sunday" is the more common of the two: it sits at frequency rank #1,287 in our English list, against #30,238 for "soundly". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "soundly" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "Sunday" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #345,374 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "soundly" and "Sunday" also get mixed up with nearby pairs, the highest-scored neighbour is "soundly vs sundry". 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 #345,374 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list