spend人作主语,某人花费多少时间或金钱。常用短语有:spend some time/ some money on/ (in) doing sth.如:I spend two hours (in) doing my homework. 或I spend two hours on my homework.cost物作主语,某件事或某个东西花费多少钱。也可表示花时间做某事:it cost sb. st. to do sth如:This coat costs me twenty yuan. It costs me twenty minutes to wash my face in the morning.