Question

If引导虚拟句

根据时态

Answer 1

虚拟语气是英语中用来表示对不可能发生的事物的一种猜测或假设的语气。英语中的虚拟语气常见的类型有:条件状语从句中的虚拟语气，后宾语从句中的虚拟语气，某些动词后宾语从句中的虚拟语气，某些结构后主语从句中的虚拟语气等。
"if"条件状语从句中的虚拟语气的结构如下表：
虚拟类型从句主句
对现在情况的假设一般过去时would+动词原形
对将来情况的假设一般过去时would+动词原形
对过去情况的假设过去完成时would + have + 过去分词
一、对现在情况的假设
主要表示对不可能发生或不太可能发生的现在情况的假设，例如：
1) If you were an Inuit near the North Pole, you would enjoy the raw meat from seals.
2) If you were a man living in the grassland, you would prefer the roasted meat of sheep or goats.
3) If you were in Germany, you would find soup that is thick and heavy.
4) If you were in China, you would find soup that is thin and clear.
以上各句所体现都是条件状语从句中的虚拟语气，表示对不可能发生或不太可能发生的现在情况的假设。
对现在情况假设的虚拟语气的构成如下：
1）条件状语从句中用were,而主句中则用would + enjoy 构成
2）条件状语从句中用were,而主句中则用would + prefer 构成
3）条件状语从句中用were,而主句中则用would + find 构成
4）条件状语从句中用were,而主句中则用would + find 构成
二、对将来情况的假设
1) If I had enough time, I would certainly go.
2) If you hurried up, you would catch that train.
3) If you studied hard in college, you would find a good job in the future.
1.如果我有足够的时间,我一定会去。
2.如果你快一点，你还会赶上那趟列车。
3.如果你在大学里努力学习，将来你就会找到一份好工作。
对将来情况的假设的虚拟语气的构成如下：
1)条件状语从句中用had,而主句中则用would + go 构成
2)条件状语从句中用hurried,而主句中则用would + catch 构成
3)条件状语从句中用studied,而主句中则用would + find 构成
三、对过去情况的假设
1) If you had begun to do your homework earlier, you would have completed them.
2) If I had listened to the teacher, I would have finished reading the English book.
3) If Tom had prepared the mid-term exam well, he would have passed it.
1)如果你早点开始做家庭作业，你早就做完了。
2)如果我听了老师的话，我该把这本英语书看完了。
3)要是汤姆为其中考试做了充分准备，这次其中考试他就及格了。
对过去情况假设的虚拟语气的构成如下：
1)条件状语从句中用had begun,而主句中则用would + have + complete构成
2)条件状语从句中用had listened ,而主句中则用would + have + finished构成
3)条件状语从句中用had prepared,而主句中则用would + have + passed 构成
四、条件句虚拟语气中的情态动词该如何选用？
条件句虚拟语气中的情态动词是否只能使用would条件句虚拟语气主句除了可使用would外还可以便用might, could和should。其中should多用于第一人称后。在美国英语中在第一人称后多用would。
1) If I have enough time, I should have finished it. 如果我有足够的时间,我会完成它的。
2) If he hadn't been ill, he might have come. 要不是生病,他可能就来了。
3) If I had been more careful, I could have done better. 我要是细心一点,是可以做得更好的。
五、条件句虚拟语气从句中的be动词的正确形式是
条件句虚拟语气中从句中的be动词不管是什么人称,多用were形式。但在非正式特别是口语中,第一、三人称单数也可以使用was。
1)If he were here now, he would give us a hand. 如果他现在在这儿，他会帮助我的。
2)If I were you, I would not go. 如果我是你,我是不会去的。
3)If she was here, we could ask her.如果她在这儿,我们可以问她。
六、条件状语从句中的虚拟语气的倒装形式是
当条件句虚拟语气的从句中含有"be, have, should, could四个词,从句可以倒装。倒装的形式是把这四个单词提前至句首，将If省略,剩下的句序不变。
1) Were I you, I would study hard. 如果我是你,我就会好好学习。
2)Had I had enough home, I would have done it better.如果我有足够的时间，我会把这件事做得更好。
3) Should John come now, what would you say to him? 如果约翰现在来,你会对他说些什么?
4)Could the dead man have spoken, he would have identified his murderer.如果死人会说话,他会认出谁是谋害他的人。

Answer 2

其实这个不难
我相信仁兄肯定也差不多
只是要区分开当"如果"和"假设"的两种情况就行
还有 注意虚拟是不可能或者几乎不可能的事情
也好区分 还有就是认真看谓语构成
我有比较个人化的语法理解
你看吧 觉得行的 就采纳
一己之见