1．should作助動詞主要用于過去將來時(shí)，用于第一人稱：

I told him that I should see her on Friday．

我告訴他星期五我會見到她。

I thought I should never see you again．

我還以為再也見不到你了。

He hoped that we should support him．

他希望我們支持他。

2．在更多情形下表示“應(yīng)該”，“應(yīng)當(dāng)”，用于各個(gè)人稱，作用接近情態(tài)動詞：

What time should we meet?

我們應(yīng)當(dāng)在什么時(shí)候碰頭?

You should do it for your own good．

為了你自己你應(yīng)該這樣做。

She shouldn't leave so soon．

她不應(yīng)當(dāng)這么快就走。

should后面有時(shí)可用完成或進(jìn)行形式：

I should have thought of it.

這一點(diǎn)我是應(yīng)該想到的。(但我沒想到。)

They should have told me．

他們應(yīng)當(dāng)事前告訴我。(但沒這樣做。)

You shouldn't be sitting here doing nothing．

你不應(yīng)當(dāng)坐在這里什么也不干。

3．用在某些從句中：

He suggested that she should come to Paris．

他建議她到巴黎來。

It will be better that he should be out of France．

他最好離開法國。

I was anxious that our plan should not fail．

我亟盼我們的計(jì)劃不失敗。

4．用在某些從句(甚至主句)中表示驚異、不以為然等情緒：

It's dreadful that they should be so miserable．

真可怕他們竟然這樣悲慘。

Why should you talk to me like that?

你怎么竟然和我這樣講話?

It's unfair that this should happen to us．

我們竟然發(fā)生這樣的事，這是不公平的。

5．用在虛擬條件句中，用于第一人稱后(這時(shí)用would時(shí)更多一些)：

I should never have done it if I hadn't been so hard up．

要不是我處境這般困難我絕不會這樣做。

We shouldn't have won without you．

要不是你我們不會獲勝。

Should I be free，1 will come．

如果我有空我會米的。

6．用在某些句子中使口氣顯得比較婉轉(zhuǎn)(a)或用來表示揣測(b)：

a．I should like to have a try．

我想試一試。(比I like．．．更委婉。)

I should think so．我想是這樣的。(比I think．．．更委婉。)

b．They should be there by now．

現(xiàn)在他們想必己到達(dá)。

The book should come out in a month．

這書一個(gè)月后估計(jì)可出版。