1.混合虚拟语气

 

If you had practiced speaking English every day, you would speak English well enough. (从句说的是过去,主句指的是现在)

如果你当初每天都练习说英语的话,你的英语就会说得很好.

2.含蓄虚拟语气

（有时假设的条件不通过条件句表达出来，而隐含在某些介词短语：如without,but for 等，或上下文，这中句子属于含蓄虚拟语气）

Without air, there would be no living things. 

相当于:If there were no air, there would be no living things.

But for your help, I couldn’t have done it.   

相当于:If you had not helped me, I couldn’t have done it.

3.虚拟语气的倒装

如果条件状语从句的谓语中有were, had或should,就可以倒装。

将were, had或should放到句首,谓语主语之前, if去掉。

变为”were/had/should+主语”的形式。如果从句没有were, had或should,就不能倒装。

If I were to do it, I’d do it some other way.→ Were I to do it, I`d do it some other way.

If you should fail, try again.→  Should you fail, try again.

If you had been here earlier, you would have seen him.→  Had you been here earlier, you would have seen him.

If you came tomorrow, we would have the meeting.这句话不能倒装.

而且,在虚拟条件状语从句中,省略了if的倒装形式的句首不能用动词的缩略形式.如:

Were it not for the expense, I would go to Italy.    但不能说:  Weren`t it for the expense, I would go to Italy.

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