Ascertain
来自Big Physics
late Middle English (in the sense ‘assure, convince’): from Old French acertener, based on Latin certus ‘settled, sure’.
wiktionary
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.
etymonline
ascertain (v.)
early 15c., "to inform, to give assurance" (a sense now obsolete), from Anglo-French acerteiner, Old French acertener "to assure, certify" (13c.), from a- "to" (see ad-) + certain "sure, assured" (see certain). Meaning "find out for sure by experiment or investigation" is first attested 1794. Related: Ascertained; ascertaining.
