9 Grammatical Pitfalls


[as-er-teyn] /ˌæs ərˈteɪn/
verb (used with object)
to find out definitely; learn with certainty or assurance; determine:
to ascertain the facts.
Archaic. to make certain, clear, or definitely known.
Origin of ascertain
1400-50; late Middle English, variant of assertain, acertain < Middle French acertain- (tonic stem of acertener to make certain), equivalent to a- a-5 + certain certain
Related forms
ascertainable, adjective
ascertainably, adverb
ascertainer, noun
ascertainment, noun
nonascertainable, adjective
nonascertainableness, noun
nonascertainably, adverb
nonascertainment, noun
preascertain, verb (used with object)
preascertainment, noun
unascertainable, adjective
unascertainably, adverb
unascertained, adjective
well-ascertained, adjective
Synonym Study
1. See learn. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for ascertain
  • They then tried to ascertain the subsequent five-year return.
  • This is not hard to ascertain.
  • The complete answer to that question is difficult to ascertain.
  • The number of illegal migrants is by definition hard to ascertain, but likely to be smaller than the legal sort.
  • The former is a lot easier to ascertain than the latter.
  • He will ascertain whether or not the exercise has been effective.
  • The names of the other four I did not ascertain.
  • Nothing has been written about this before as far as I have been able to ascertain, so the exercise is purely academic.
  • I'd ask to speak with the student about the quiz and try to ascertain what the word meant to the student.
  • That's why there isn't a way to ascertain the numbers with certainty.
British Dictionary definitions for ascertain


verb (transitive)
to determine or discover definitely
(archaic) to make certain
Derived Forms
ascertainable, adjective
ascertainably, adverb
ascertainment, noun
Word Origin
C15: from Old French acertener to make certain
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for ascertain

early 15c., "to inform, to give assurance," from Anglo-French acerteiner, Old French acertener "to assure, certify" (13c.), from a "to" (see ad-) + certain "certain" (see certain). Modern meaning of "find out for sure by experiment or investigation" is first attested 1794. Related: Ascertained; ascertaining.

Online Etymology Dictionary, © 2010 Douglas Harper
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