虚拟语气 -if 引导的非真实条件句
1. 真是条件句和非真实条件句
一般而言, 虚拟语气用于条件状语从句中是考生们最常见、最常考到的虚拟语气语法点。

此种虚拟语气形式也就本课件特定讲解的“ if 引导的非真实条件句之
虚拟语气” 。

再讨论此类虚拟语气之前,有必要说明一点:并非所有包含“ if 引导的非真实条件” 从句的句子都是虚拟语气句子。

在英语中, 虚拟语气表示动作或状态与事实相反, 或不可能发生的情况。

因此要判断类似句子是不是虚拟语气, 通常的标准是:假设条件不符合客观事实或者实现的可能性极其微小的, 通常就是虚拟语气;反之则
不是。

请理解区别以下句子:
(1If you don’ t hurry up, you will miss the bus. 如果他不快点, 他将错过巴士。

( 真实
(2If I were you, I would go at once. 如果我是你,我马上就会去。

(非真实, 虚拟语气
2. 虚拟语气用于条件状语从句中
1 if 假设的条件与现在事实相反或不可能发生。

则条件状语从句用一般过去时(任何 be 动词的原来形式一律改用 were ,主句用“ would(should, could, might+动词原形” 。

请理解以下句子:
(1 If I were you, I would work hard.
(2 If we had time, we could play the game again.
2 if 假设的条件与过去事实相反或不可能发生。

则条件状语从句用“ had+过去分词主句” ,主句用“ would(should, could, might+have+过去分词” 。

请理解以下句子:
(1 If he had taken my advice, he would have passed the exam.
(2 If I had known your telephone number, I would have called you.
3 if 假设的条件与将来的事实可能相反或不可能发生:条件状语从句:①
一般过去时 , ② “ should +动词原形” , ③ “ were to+动词原形” ; 主
句:“ would(should, could, might+动词原形” 。

其中①的情况包括一些在条件状语从
句中用一般时表示将来时的特殊动词和动词词组, 如“ go , arrive , come , leave , start , stay , return, play, do, have, work, wear, spend, see, meet, there be”等,请随带记忆。

请理解以下句子:
(1 If there were rain tomorrow, the game would be put off.
(2 If it were to snow tomorrow, they would not go out.
(3 If it should rain tomorrow, I would stay at home.
P.S 省略 if 的虚拟语气
如果从句中含有 were/ should/ had时, 则可以把这三个词置于句首, 省略 if , 并
在从句中采用倒装语序。

请理解一下句子。

(1 If she were here, she would agree with us. → Were she here, she would agree with us.
(2 If it should happen, what would you do? → Should it happen, what would you do?
(3 If he had recognized me, he would have come over. → Had he recognized me, he would have come over.
3. 总结
以上 3大类情况属于 if 引导的非真实条件句的虚拟语气的常见基本形式, 但其所有形式绝不仅限于此。

如:
If you had followed my advice, you would be better now. 这显然是假设条件与过去相反, 而主句表达现在情况的混合虚拟语气句, 并且没有任何语法错误。

因此需要说明的是,要学好虚拟语气,对句意的理解才是根本。