certain
I am certain about my decision.
I am very confident and sure about my choice.
having no doubt; sure
She is certain of her success.
She is confident and sure that she will succeed.
Often used to express strong confidence or assurance.
a specific but unspecified person or thing
A certain someone left a gift at my door.
An unspecified person left a gift at my door.
Used to refer to someone or something without naming them directly.
Collocations
Related Phrases
Pro Tip
Usage Tip
Use 'certain' to express strong confidence or to refer to an unspecified person or thing.
Gold Rule
Grammar Rule
'Certain' can function as both an adjective and a determiner, but its meaning changes based on context.
Word Origin
From Old French 'certain', from Latin 'certus', meaning 'determined, resolved, sure'.
Usage Notes
Can be used as an adjective to describe a state of confidence or as a determiner to refer to an unspecified person or thing.