Ascertain Meaning
/ˌæsəˈteɪn/Definition, CEFR level C1, pronunciation, examples, and quiz.
Listen pronunciation
Definition
verbTo find out definitely; to discover or establish.
verbTo make (someone) certain or confident about something; to inform.
Sentence Examples
We will first ascertain the cause of the disaster.
As I heard the story secondhand, I can't ascertain the truth of it.
CEFR Practice Quiz
The detective tried to ____ the exact cause of the fire by examining the evidence.
CEFR Practice Quiz (Alternate)
The police are trying to ____ the exact cause of the sudden accident.
Word Origin & History
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.
Literary Quotations & Historical Citations
"“There the cause of death was soon ascertained ; the victim of this daring outrage had been stabbed to death from ear to ear with a long, sharp instrument, in shape like an antique stiletto, which […] was subsequently found under the cushions of the hansom.[…]”"
— 1904–1905, Baroness Orczy [i.e., Emma Orczy], “The Tremarn Case”, in The Case of Miss Elliott, London: T[homas] Fisher Unwin, published 1905, →OCLC; republished as popular edition, London: Greening & Co., 1909, OCLC 11192831, quoted in The Case of Miss Elliott (ebook no. 2000141h.html), Australia: Project Gutenberg of Australia, February 2020:
"Walk the dog in the pounding rain / Looking for a way out of my brain, trapped in it / But I cannot ascertain that I'm trapped in it / Or that the traps even real so I remain trapped in this chambers"
— 2023, “Split The Atom”, in Kae Tempest (lyrics), Nice Idea:
""[…] On the 18th of October, 1841, a very intense magnetic disturbance was recorded, and amongst other curious facts mentioned is that of the detention of the 10:05pm express train at Exeter for 16 minutes, as from the magnetic disturbance affecting the needles so powerfully, it was impossible to ascertain if the line was clear at Starcross. The superintendent at Exeter reported the next morning that someone was playing tricks with the instruments, and would not let them work.""
— 2023 November 15, Prof. Jim Wild, “This train was delayed because of bad weather in space”, in RAIL, number 996, page 30:
"Therfore the saide cõmissioners shall mowe say that nowe late during the parlement the King ascertaigned of the saide maliciouse pʳpose of his enemys, willed and desired the lords being then present to shewe their̃ good willes aide and helpe for the saide rescues[…]"
— 1436, Sir Nicholas Harris Nicolas, editor, Proceedings and Ordinances of the Privy Council of England, volume IV, published 1835, page 352c:
"We would most gladly ye came yourself if that ye may […] praying you to ascertain us of your News."
— 1844 [1483], Caroline A. Halsted, quoting Richard III, chapter XV, in Richard III as Duke of Gloucester and King of England, page 307:
Explore More C1 Vocabulary Words
CEFR Practice Quiz
The detective tried to ____ the exact cause of the fire by examining the evidence.
CEFR Practice Quiz (Alternate)
The police are trying to ____ the exact cause of the sudden accident.