spend（in）doing sth和on doing sth 的区别？

Question

为什么看到有的是on有的是in?

Answer 1

spend ...(in) doing sth.表示‘花钱/ 时间做某事’spend ...on doing sth. 表示‘在某方面的花费’e.g. 1. He often spends two hours (in) listening to English .（听英语所花费的时间） 2. He often spends 100 yuan on books and newspapers every month.(在书报方面的花费）

Answer 2

就是你后面的宾语要是名词，就用On，要是动词，就用（IN）doing.

Answer 3

spend....(in) doing sth, spend...on sth, 如果用on的话，后面直接跟名词，跟动作要用doing