Other forms: ascertained, ascertaining, ascertains
To ascertain is to find out for certain. Ascertain the facts, hard to ascertain, ascertain whether it is true.
It is formal and belongs to reports and official language, where find out is what anybody says. The certain inside it is doing real work: ascertaining is establishing beyond doubt rather than merely discovering.
1verbascertainTo find out for certain.
“The police are still trying to ascertain the cause of the fire.”
ascertain is a finding out.
Old French acertener means to make sure of, from certain, from Latin certus, settled.
Proto-Indo-European
*krey-
Latin
certus — certain, fixed
Old French
acertener
Middle English
acerteynen
English, today
ascertain
Built from
From Middle English acerteynen, from Old French acertener, from a- (“to, towards”) + certener (“make sure of”), from the adjective certain, from Latin certus (“certain, fixed”). Compare to Spanish acertar.
Etymology from Wiktionary, CC BY-SA