verb
ascertain
a-suh-TAYN
verb
1
To find out or establish something for certain, usually through checking or investigation.
"Investigators worked to ascertain the cause of the fire."
"Please ascertain whether the shipment has arrived before calling the client."
How to Use Ascertain
Learner’s notesIn plain EnglishTo check and confirm a fact rather than just assume it.
When to use it
Fairly formal; "find out" or "check" is more natural in everyday speech.
Common pairings
ascertain the facts
ascertain whether
difficult to ascertain
Word Forms
ascertained past tense, ascertains singular
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Investigators worked to _____ the cause of the fire.
Etymology
From Old French acertener, "to make certain," ultimately from Latin certus ("certain, sure") — the same root as "certain."