预测一：虚拟语气在 if 非真实条件句中的规则变化

非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。

	从句	主句
与现在事实相反	did/were	would (should/could/might) do
与过去事实相反	had done	would (should/could/might) have done
与将来事实相反	did/were; were to do; should do	would (should/could/might) do

 

预测二：if 非真实条件句的倒装

虚拟条件句的从句部分含有 were，should 或 had 时，可省略 if，再把 were，should 或 had

移到从句的句首进行倒装。例如：

Were they here now, they could help us. = If they were here now, they could help us.

他们现在要是在的话，就会帮助我们了。

Had you come earlier, you would have met him. =If you had come earlier, you would have met

him. 你来得早一点，就碰到他了。

Should it rain, the crops would be saved. =Were it to rain, the crops would be saved.

 

假如下雨，庄稼就有救了。

预测三：错综时间条件句的虚拟语气

有时，主句与从句的动作发生在不同的时间，主句从句谓语动词的虚拟语气形式因时间不

同而不同，这种条件句叫做错综时间条件句。例如：

If you had asked him yesterday, you would know what to do now. 如果你昨天问过他，今天就

知道做什么了。(从句与过去事实相反，主句与现在事实相反。)

If it had rained last night, it would be very cold today. 如果昨晚下过雨，今天就会很冷了。

预测四：含蓄条件句的虚拟语气

有时为了表达的需要，在虚拟语气中并不总是会出现 if 引导的条件句，而是通过其他手段

来代替条件句。其主要表现形式如下：

用 with, without, but for, otherwise, or, under 等代替条件状语从句。例如：Without water, there would be no life. 若是地球上无水，就无生命。

But for the meeting, I would have gone home at the time. 要不是开会，我早就回家了。

I was too busy at that time, otherwise, I would have called you. 我当时太忙，否则我就给你打电话了。

预测五：名词性从句中的虚拟语气

(1)It is demanded (requested/required/insisted/suggested/proposed...) /important (essential/

necessary/natural/imperative...) / a pity (a shame/no wonder...) + that... 等结构的主语从句，谓语动

词用 should 加动词原形，should 可省略。例如：

It is demanded that the president (should) make measures to end the economic recession.

人们要求总统应该采取措施阻止经济衰退。

It is necessary that he (should) go to see a doctor. 他应该去看医生，这是必要的。

It is a pity that he (should) fail to come to the party. 他没能参加这个聚会，真是遗憾。

(2)用于宾语从句中

在表示命令、建议、要求(如 demand, command, request, require, insist, suggest, propose,

order, recommend)等一类动词后面的从句中，谓语动词用 should 加动词原形，should 可省略。

例如：I suggest that we (should) hold a meeting next week. 我建议下周召开个会议。

He insisted that he (should) be sent there. 他要求被派到那儿去。

 

注意：若 suggest，insist 用于其本意 “ 暗示、表明 ”“ 坚持认为 ” 时，宾语从句用陈述语气。

例如：Your pale face suggests that you are ill./ I insisted that you were wrong.

(3) 在 demand/command/request/requirement/insistence/suggestion/advice/proposal/recom

mendation/idea/plan/order 等表示要求、建议和命令等名词后面的表语从句、同位语从句中的动

词要用虚拟语气，即(should)+ 动词原形。例如：

My idea is that we (should) get more people to attend the conference. 我的想法是让更多的人来参加会议。