托福语法详解之虚拟语气应该怎么去掌握？大家在学习英语的时候，对于虚拟语气肯定是有非常深刻的印象，毕竟这个也是英语中的一个难点了，而且我们在阅读文章的时候会发现有大量的这个句子。

托福语法详解

虚拟语气在托福考试的考点中不是那么的重要，但是鉴于它的活跃表现，我们对它还是要有一定的了解的，这对于解读也是很有帮助的。

菠萝在线小编今天就给大家说说虚拟语气，虚拟语气是英文中一种特殊的语言现象，其主要是用来表达与事实相反的一个陈述，所表达的一个强烈的愿望、遗憾、感慨、后悔、责备等等的一些语义，虚拟语气大致可以分为三类：

一、对现在事实的虚拟

其基本的形式为：If+were/did等的过去式...，..would/could/should/might+do。比如像：If I were a bird, I would fly to the moon.

(真实情况是： I 'm not a bird, so I will not fly to the moon.)

二、对过去事实的虚拟

其基本的形式为：If+had done...，..would/could/should/might+have done。比如像：If she had been warned earlier, she wouldn't have broken the rules.

(真实情况是：She was not warned earlier and She broke the rules.)

小编贴士：这种的虚拟是可以进行倒装的。比如像：Had the letter been sent out, it would have our friendship train.其等于：

If the letter had been sent out, it would have thought our friendship.

三、对将来事实的虚拟

其基本的形式为：If+should do...，..would/could/should/might+do，这个意思就有点像我们常说的“万一”。比如像：If he should forget the date, I might teach him a good lesson.（真实情况是：He is unlikely to forget the date.）

小编贴士：这种虚拟也是可以进行倒装的。Should my car fail, I would have to return home on foot.

其等于：If my car should fail, I would have to return to home on foot.

托福语法详解

注意事项

一、部分动词的宾语从句中需要用虚拟语气，形式是should do，但是其中常常会省略掉should。这一类的动词有insist, demand, suggest, withdraw, order, require, decide, ask, request等等。使用的时候像这样：The professor suggested that the students (should) collect enough materials before they work on this project.不过，如果上面提到的动词是以名词形式出现的时候，后面的that从句仍然是要用虚拟语气的。比如像：He gives me the suggestion that I (should) eat breakfast every moning.

二、在一些惯用语的后面也是经常需要用到虚拟的，以此来表示与事实相反或者难以实现的事情。这一类的习语有：as if, as though, but for, otherwise, without, wish, if only等等。使用的话像：But for your help, I would not have arrived here in time.,

三、在一些形容词引导的that从句里面必须要用虚拟语气（should）do，但是由于should经常是被省略的，所以实际上用的就是动词原形,像这一类的形容词有：It is important/necessary/proper/imperative/essential/advisable等+that。这种句子有：It is necessary that he (should) realize his situation.

照例，为了让那个各位有个更加清晰的认识，菠萝在线来进行例题解析：

例：Abraham Lincoln insisted that --- not just on mere opinion but on moral purpose.

(A) to the base centre

(B) for democracy to be based

(C) the centre be -based

(D) clean democracy is based

解析：在题目里面，动词insist的后面的宾语从句需要用虚拟语气，从句谓语应该是should do或者（should）do，而在选项里面，只有C符合要求，谓语是动词原型，所以选C。

托福语法详解中的虚拟语气这部分也是非常重要的，而且我们需要注意很多的东西，这一块学习起来是一个难点，大家在备考的时候一定要重点复习。