# s vs SI

> English confusable word pair

## The two words

### s
*character · IPA /ɛs/ · frequency rank #142*
The nineteenth letter of the English alphabet, called ess and written in the Latin script.

### SI
*name · frequency rank #5,453*
International System of Units

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