soft-soap - use flattering talk on somebody

praise - express approval of; "The parents praised their children for their academic performance"

adulate - flatter in an obsequious manner

stroke - treat gingerly or carefully; "You have to stroke the boss"

bootlick, kotow, toady, truckle, kowtow, fawn, suck up - try to gain favor by cringing or flattering; "He is always kowtowing to his boss"

brown-nose, butter up - flatter with the intention of getting something