know for certain

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“So you don’t really know for certain how many vessels and what volume they’re carrying. There’s a question mark there.”

From The Wall Street Journal • Jul. 1, 2026

If we don’t know for certain whether brain training can lower the risk of dementia, but it might just, then why wouldn’t we do it?

From MarketWatch • Feb. 11, 2026

Given the lack of any count over time, it’s impossible to know for certain how agents’ current use of the banned and dangerous tactics compares with earlier periods.

From Salon • Jan. 14, 2026

But the plaintiffs had doctors testify that they could not know for certain whether an infant with these defects would live for days, weeks, or maybe even a few months before suffering a painful death.

From Slate • Jan. 10, 2026

We shall never know for certain because in 1906 he was fatally run over by a carriage while crossing a Paris street.

From "A Short History of Nearly Everything" by Bill Bryson