ascertain vs spot-check

ascertain and spot-check both are verbs.

Word	Noun	Adjective	Verb	Adverb
ascertain	No	No	Yes	No
spot-check	No	No	Yes	No

As verbs, spot-check is a hyponym of ascertain; that is, spot-check is a word with a more specific, narrower meaning than ascertain:

ascertain: be careful or certain to do something; make certain of something
spot-check: pick out random samples for examination in order to ensure high quality

Other hyponyms of ascertain include proof, proofread, control, double-check, cross-check, cinch, card, cover.

ascertain (verb)	spot-check (verb)
be careful or certain to do something; make certain of something	pick out random samples for examination in order to ensure high quality
learn or discover with certainty
find out, learn, or determine with certainty, usually by making an inquiry or other effort
establish after a calculation, investigation, experiment, survey, or study