Words / C1

as-uh-TAYN/ˌæsəˈteɪn/

To ascertain is to find out so that you are sure — a formal establish the facts. You ascertain the number, the cause, whether + clause. Find out is everyday; check is smaller. Determine is close in academic English. Ascertain belongs in reports, inquiries, and careful emails, not in “I’ll ascertain if the café is open.”

Meaning

To find something out for certain.

Examples

• “We need to ascertain the exact number of students.”
• “The inquiry could not ascertain who signed the form.”
• “Please ascertain whether the room is free on Friday.”

Good to know

Formal for find out for certain. ascertain whether/that. Everyday: find out / check.

Near in meaning

establish

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