1）表示出于职责、义务该做某事
You shouldn't come to such a decision hastily .
你不应该匆匆忙忙地作出这么一个决定。
You should write to your parents at least once a month .
你应该至少每月给你父母亲写一封信。
We should read English aloud every morning .
我们应该每天早晨朗读英文。
They should do it for their own good .
为了他们自己利益他们应该做这件事。
2）表示对某种情况的估计
She shouldn't be out in such an early morning .
她不会这么一大早就出去了吧。
The effect of the tax should be felt in higher prices .
人们可能会从各种上涨的物价中感觉到这种税的影响的。
The event should lead them to a even worse economic crisis.这次事件可能会将他们引向更严重的经济危机。
This book should be published in two months at most .
这本书最多两个月后就会出版的。
3）表示惊讶、失望等情绪
I think it is dreadful that anyone should be so miserable.
我认为，竟然每个人都如此伤心就太糟糕了。
Why should I pay him for nothing ? 我干吗要无为地付给他钱？
It seems so unfair that this should happen to me .
这件事竟然发生在我身上似乎太不公平了。
It's strange that it should be so cold today .奇怪，今天怎么会这么冷。
4）用于某些从句中表示虚拟语气
The doctor insisted that the girl should be hospitalized .
大夫坚持认为那个女孩要住院治疗。
If it had not been for the doctor's care the girl should not be speaking to you now .要不是由于大夫的精心照料，这个女孩现在就不能与你说话了。
She stood away so that he should enter the room first .
她让到一边，好让他第一个进入房间。
I'll write it down lest I should forget it 我将它记下以免遗忘。
Take an umbrella with you in case it should rain .
带上雨伞，以防万一下雨。
