Question

there are two main reason 后面一定要加for吗

Answer 1

看语意：

一般来说是的

但是也有从句的情况,也有在句尾的情况,看例子：

1.There are two main reasons for checking-in as much as possible.

主要有两大主要理由.

2.There are two main reasons why crunch hurts a project like ShortHike.

其一是,长时间的工作虽然短期内会提高你的产出,但是最终却会损失更多.

3.My answer was that there were two main reasons.

我回答说,主要有两条.

PS：there are two main reasons