sou vs sub, What's the Difference?

Which to use

“sou” and “sub” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#35,525
“sou” frequency rank: #2,236
“sub” frequency rank: 37761
confusion score

Side-by-Side Comparison

Feature	sou	sub
Definition	An old French copper coin equal to one twentieth of a livre or twelve deniers; one sou is to the livre as one shilling is to the pound.	Abbreviation of submarine.

Where the eye mixes sou and sub

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch

sou

3 ch

sub

Visual trap between sou and sub

A purely visual mix-up. sou (/suː/) and sub (/sʌb/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 37761, derived from the frequency rank of both members and their visual similarity.

sou is recorded at frequency rank #35,525, classified as anoun, pronounced /suː/. sub is at rank #2,236, tagged as anoun, pronounced /sʌb/.

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 37761, this pair ranks #291,732 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of sou vs sub

Shared letters: su. Private to "sou": o. Private to "sub": b.

"sou" · 3 letters · shape CVV · "sub" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "sou" for "sub" ever safe?

No. They are said differently (/suː/ versus /sʌb/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.

In ordinary English text, does "sou" or "sub" show up more?

"sub" is the more common of the two: it sits at frequency rank #2,236 in our English list, against #35,525 for "sou". 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 "sou" and "sub" is sorted above. Next: full entries or other pairs that share a letter shape.

Full dictionary entry for "sou" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "sub" - compare definitions side by side with the headword page. Word entry
This pair ranks #291,732 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"sou" and "sub" also get mixed up with nearby pairs, the highest-scored neighbour is "Sif vs sou". Nearby pair

Confusion rank #291,732 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.