# su vs sub

> English confusable word pair

## The two words

### su
*noun · frequency rank #8,094*
Alternative form of xu (“former Vietnamese currency”).

### sub
*noun · IPA /sʌb/ · frequency rank #2,236*
Abbreviation of submarine.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/su-vs-sub