-ster,-eer,-er(or) 意为:从事某种职业或参与某种活动的人(person engaged in an occupation or activity)例词:gamester,gangster,songster,engineer,profiteer,mountaineer,auctioneer,driver,teacher,director,actor,professor
-ive 意为:有……属性的;有某种倾向的(having the nature or quality of;given or tending to)例词:attractive, talkative,restrictive,defensive,preventive,constructive,sensitive