sourvssourceTell them apart

Quick tell: sour is a adjective, source is a noun, so they fill different roles in a sentence.

Which to use

“sour” is an adjective and “source” is a noun - they look or sound alike but fill different roles in a sentence.

#8,610
“sour” frequency rank
#743
“source” frequency rank
9353
confusion score

Side-by-Side Comparison

Feature sour source
Definition Tasting of acidity. The person, place, or thing from which something (information, goods, etc.) comes or is acquired.

Where the eye mixes sour and source

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.

4 ch
sour
6 ch
source

Why the eye confuses sour with source

These two trip readers on the page rather than in the ear: sour is /ˈsaʊə/ while source is /sɔːs/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “sour” sits inside “source”, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 9353, derived from the frequency rank of both members and their visual similarity.

sour is recorded at frequency rank #8,610, classified as anadj, pronounced /ˈsaʊə/. source is at rank #743, tagged as anoun, pronounced /sɔːs/.

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 9353, this pair ranks #497,851 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of sour vs source

Shared letters: orsu. Private to "sour": -. Private to "source": ce.

"sour" · 4 letters · shape CVVC  ·  "source" · 6 letters · shape CVVCCV

Known mistypes of this pair

  • sourosur · soru · sourr · ssour · suor
  • sourceosurce · soruce · soucre · sourcce · sourec · sourrce · ssource · suorce

Frequently Asked Questions

Can "sour" and "source" be used interchangeably?
No - they are not even the same part of speech. "sour" is an adjective and "source" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "sour" or "source"?
"source" is the more common of the two: it sits at frequency rank #743 in our English list, against #8,610 for "sour". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Eye-level mix-up between "sour" and "source" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "sour" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "source" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #497,851 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "sour" and "source" also get mixed up with nearby pairs, the highest-scored neighbour is "sour vs sura". 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 #497,851 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