# so vs su

> English confusable word pair

## The two words

### so
*conjunction · IPA /səʊ/ · frequency rank #33*
Reduced form of 'so that', used to express purpose; in order that.

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

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/vs/so-vs-su