guarantee, vouch - give surety or assume responsibility; "I vouch for the quality of my products"

doom - make certain of the failure or destruction of; "This decision will doom me to lose my position"

make - assure the success of; "A good review by this critic will make your play!"

proofread, proof - read for errors; "I should proofread my manuscripts"

check off, tick off, mark off, tick, check, mark - put a check mark on or next to; "Please check each name on the list"; "tick off the items"

control - verify by using a duplicate register for comparison; "control an account"

check - verify by consulting a source or authority; "check the spelling of this word"; "check your facts"

double-check - check once more to be absolutely sure

cross-check - check out conflicting sources; crosscheck facts, for example

cinch - make sure of

card - ask someone for identification to determine whether he or she is old enough to consume liquor; "I was carded when I tried to buy a beer!"

spot-check - pick out random samples for examination in order to ensure high quality

verify - confirm the truth of; "Please verify that the doors are closed"; "verify a claim"

ascertain, find out, learn, watch, determine, see, check - find out, learn, or determine with certainty, usually by making an inquiry or other effort; "I want to see whether she speaks French"; "See whether it works"; "find out if he speaks Russian"; "Check whether the train leaves on time"

cover - maintain a check on; especially by patrolling; "The second officer covered the top floor"

verify, control - verify or regulate by conducting a parallel experiment or comparing with another standard, of scientific experiments; "Are you controlling for the temperature?"