# sis vs so

> English confusable word pair

## The two words

### sis
*noun · IPA /sɪs/ · frequency rank #12,501*
Clipping of sister.

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

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