pay for
sb. spend some money in doing sth.
sth. costs sb.some money
spend
spend some money on sth
spend some time (in) doing sth
cost
it cost sb some time to do sth
pay
sb pay some money for sth
spend:(花钱+on、花时间+in)
1、sb. spend some money on sth.
eg.I spend 1 yuan on the pen.
2、sb. spend some time in doing sth.
eg. He spends two hours in finishing his homework.
3、sb. spend some time in (doing) sth.(重点)
eg.Though I spend much time in math ,I still got "c" for it.
(误区:一般人认为表sth.的"math"前应加on,但是这里是把math前的动词省略的缘故造成的误区。判断方法:表花时间做某事用in,花钱买某物就用on,这个应该很快就能判断出来了,就不会造成误选,这是考试最常考到的,要注意啊)
cost(+to do)
1、sth. cost sb..(宾语形式) some money.(花钱买某物)
eg.This book cost me 10 dollars.
2、It cost sb.(宾语形式) some time to do sth.(花时间做某事)
eg.It cost me 2 hours to finish the homework.
pay(+for)
1、sb. pay some money for sth.( 某人花钱买某物)
eg: I pay 10 dollars for this book.
希望以上归纳对你有用啦。。。