should 是情態動詞,后接動詞原形。should譯為應該；大概是，有可能；將會，shall，can, may,must等都是情態動詞，它們不能獨立作謂語，只能和動詞原形一起構成謂語。舉例：People should diversify their investments.人們應分散投資在幾家公司。should there be a flood, what should we do? 萬一發生水災我們怎么辦？

Should的用法

1.should后直接跟動詞原形，沒有人稱和數的變化, 如：

You should go home at once.He should eat more vegetables.I should finish my homework before nine.should的否定形式是在should后面加not, 可以縮寫為shouldn’t, 意為“不應當; 不應該”。如:You should not / shouldn’t insult her. 你不應該羞辱她。

2.should作為情態動詞最基本的意思是“應該”，既可指建議或勸告某人“應該”做某事，也可指有責任或義務“應該”做某事，如：You should tell your mother. 你應該告訴你的媽媽。

3.should可以與say, think, imagine等動詞連用，使語氣變得委婉，如：I should say he is an English teacher. 我想他是一位英語老師。I should think it is a good song. 我想那是一首好曲子。

`But what should I sing?' she interrupted him, keenly.

“可是我該唱什么呢？”她打斷他的話，滿心期待地問。

Dolly is myopic and should see an optician.

多莉是近視眼，應該看看眼科醫生。

He should get an uncontested lead.

毫無疑問，他會獲得領先。

4You should have seen him, it was hysterical!

你真該看看他的樣子，那真是樂死人了！

5The boxes should be constructed from rough-sawn timber.

這些箱子應該用粗鋸木料來做。