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.

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

Forecasting snow in the UK is notoriously difficult, and it is still too early to know for certain whether we will see a white Christmas in 2025.

From BBC • Dec. 12, 2025

We can’t know for certain if the Values Bridge data reveals a slow trend away from the centrality of family in the American psyche or a sudden drop, or why in either case.

From The Wall Street Journal • Nov. 20, 2025

The next year Descartes formulated his famous doctrine cogito ergo sum, ‘I think therefore I am’; consequently, there is something, one thing, I know for certain.

From "The Invention of Science" by David Wootton