# certain

> English word · Adjective · IPA /ˈsɜː.tən/ · frequency rank #707

## Definitions
1. Sure in one's mind, positive; absolutely confident in the truth of something.
2. Not to be doubted or denied; established as a fact.
3. Sure to happen, inevitable; assured.
4. Unfailing; infallible.
5. Fixed; regular; determinate.
6. Particular and definite, but unspecified or unnamed; used to introduce someone or something without going into further detail.
7. Used to denote that the speaker is referring to a specific person or thing that they do not want to name directly, implying that the listener should infer the identity of the referent.
8. Named but not previously mentioned.
9. Used before the name of someone famous that people are expected to know.
10. Determined; resolved.

## Etymology
From Middle English certeyn, certein, certain, borrowed from Old French certain, from a Vulgar Latin unattested form *certānus, extended form of Latin certus (“fixed, resolved, certain”), of the same origin as cretus, past participle of cernere (“to separate, perceive, decide”). Displaced native Middle English wis, iwis (“certain, sure”) (from Old English ġewiss (“certain, sure”)) and alternative Middle English spelling sertane (“some, certain”).

## Easily confused with
- **Curtin** (https://plainspell.com/en/vs/certain-vs-curtin)
- **contain** (https://plainspell.com/en/vs/certain-vs-contain)
- **curtain** (https://plainspell.com/en/vs/certain-vs-curtain)
- **curtail** (https://plainspell.com/en/vs/certain-vs-curtail)
- **curtains** (https://plainspell.com/en/vs/certain-vs-curtains)
- **certainly** (https://plainspell.com/en/vs/certain-vs-certainly)
- **certainty** (https://plainspell.com/en/vs/certain-vs-certainty)
- **captain** (https://plainspell.com/en/vs/captain-vs-certain)

## Common misspellings (10)
`ccertain`, `ceratin`, `cerrtain`, `certainn`, `certani`, `certian`, `certtain`, `cetrain`, `cretain`, `ecrtain`

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