spend, take, pay, cost的区别
（1）spend的主语通常是人，往往用于句型(sb.) spend some money/some time on sth. / (in) doing sth.如：
He spent three days on the work. = He spent three days (in) doing the work.
（2）take常用于“占用、花费”时间，其主语通常为形式主语“it”或物。句式是：It takes / took sb. some time to do sth = Sth. take(s) / took sb. some time. 如：
It took me three years to draw the beautiful horses.
The work took me two days.
（3）pay为“付款、赔偿”之意，主语通常是人，往往是sb. pay some money for sth.或pay sb. (some money for sth)。如：
He has paid the doctor 50 pounds for the medicine.
How much did you pay him?
（4）cost的主语必须是某物。句型是sth. cost (sb.) some money。如：
The dictionary cost me 20.