新东方名师：大学英语四级考试语法提纲

　　I should have practiced more (than I did)! (完成)

　　我应该多多练习!(言下之意，现在我练习得不多。)

　　I shouldn't dream away my time too much! (完成的否定)

　　(actually I did dream away my time too much!)

　　It shouldn't have been leaking for such a long time! (完成进行)

　　I may/might/could have finished! (完成)

　　一些常见的句型中，就会出现这种虚拟语气，而处于从句之中，should 常常被省略掉

　　o suggest, advise, propose, recommend, plan;

　　o demand, order, direct, arrange, command, decide;

　　o require, request;

　　o think, expect, believe, insist, suspect.

　　由于他们的含义中包含"建议，假设，应该"这类的含义，所以，由他们引起的从句中，就会包含有should+原型时态构成的虚拟语气。

　　这些动词(以及他们的名次形式，分词形式)引起的从句还有其他的变形：

　　主语从句，表语从句，同位语从句

　　It's suggested that…

　　My suggestion is that…

　　The only suggestion that...

　　The only suggestion I can give you now is that…

　　一些形容词引起的表语从句中，也会有同样的情况

　　important; necessary; essential

　　It's natural ; strange; incredible that

　　a pity; a shame; no wonder

　　? 由lest, for fear that, in case 引起的从句中多使用should

　　v 表达与事实相反

　　1. 与现在相反：使用[过去时]：

　　I wish I were not here! (一般现在à一般过去)

　　Suppose we were not here.

　　He loved me as if I were his own son. (一般现在à一般过去)

　　Hope I weren't always losing things! (现在进行à过去进行)

　　If only/If I hadn't been there! (现在完成à过去完成)

　　What if I hadn't been waiting right here! (现在完成进行à过去完成进行)

　　常考句型：It's (high) time (that)…; would rather (that)…

　　这两个从句，只能表达对现在的看法，所以，从句中只有一般过去时。

　　2. 与过去相反：过去完成时;

　　How nice it is if I had past the test!

　　How nice it is if I had slept a little more this morning!