know for a fact
Have definite proof
To know for a fact is to be certain of something, not merely to believe or suspect it.
The phrase emphasizes that the speaker has direct knowledge or proof: I know for a fact she was there—I saw her myself.
It often prefaces claims the listener might doubt: I know for a fact he's been lying to us.
- truthAccordance with reality
- certaintyTotal absence of doubt
- dead certainUtterly confident in belief
- beyond doubtProven completely true
- no questionComplete certainty expressed
corroboration · evidence · hard evidence · confirmation · statement · verification · substantiation · sworn testimony · eyewitness account · credibility · take my word · firsthand · awareness · indisputable · authentication · proof · claim · perception
know for a facthave no idea
Lack all knowledge
guess · assume · not have the faintest idea · doubt · speculate
know for a facttake someone's word for it
Accept a claim unverified
hear through the grapevine · jump to conclusions · take for granted · make up · fabricate
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