# certain vs contain

> English confusable word pair

## The two words

### certain
*adjective · IPA /ˈsɜː.tən/ · frequency rank #707*
Sure in one's mind, positive; absolutely confident in the truth of something.

### contain
*verb · IPA /kənˈteɪn/ · frequency rank #2,984*
To hold inside.

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