Certain

/ˈsɜːrtn/

adjectiveBeginnerVery CommonGeneral

Definitions

2 meanings
1

Having no doubt; sure.

/ˈsɜːrtn/

adjectiveneutralBeginner
General

Free from doubt; sure.

I'm certain I locked the door.

💡 Simply: It means you know something for sure, like knowing the sun will rise tomorrow. If you're certain about something, you're 100% sure!

👶 For kids: You know it's true!

More Examples

2

Are you certain you saw him?

How It's Used

General

"I'm certain he's telling the truth."

Mathematics

"It is certain that 2 + 2 = 4."

2

Specific; particular.

/ˈsɜːrtn/

adjectiveneutralIntermediate
General

Fixed; definite; particular.

A certain amount of money is needed.

💡 Simply: It means a specific thing or time, like a certain store or a certain time of day. It points to one specific thing among many.

👶 For kids: One special thing.

More Examples

2

For certain reasons, I couldn't attend.

How It's Used

General

"On a certain day, she decided to leave."

Tip:Think of it as 'a specific one'.

Idioms & expressions

for certain

Without any doubt; certainly.

"I know for certain he's guilty."

From Old French certeyn, from Latin certus "sure, certain, fixed".

The word's usage has remained relatively consistent throughout history, primarily focusing on expressing certainty and specificity.

Memory tip

Think of 'certain' as 'secure' in your knowledge.

certiancirtainsertin

Usage

60%Spoken
40%Written