一、if从句： 即 主句, if 从句

　　1、倒装代替if从句：Had/Were/Should ，主句

　　2、but for = without(如果不是)代替if从句， 两个都是介词 But for \without + 名词 ，主句

　　3、with + 名词 ，主句

　　4、if only + (if 从句) 要是该多好

　　二、宾语从句：

　　1、I suggest(表示命令;建议;请求) that shoule +do (在虚拟语气中，shoule have done = ought to have done,其他时候should 不等于ought to) 2、I wish that (用虚拟语气)

　　三、目的状语：

　　Lest或者for fear that + (虚拟语气)should do

　　四、 主语从句：

　　1、it is +adj/n that + 虚拟

　　2、it is +done(表示建议、要求)that + 虚拟

　　五、隐藏虚拟语气：本打算做但结果没有做的

　　1、had hoped/intended/planned/expected/wanted/meant to do

　　2、hoped to have done

　　3、be(was/were) + to have done 4、would/should like to have done Would have done 表意愿、将来

　　Should have done 竟然做了、本应该做的 Could have done 有能力做 Might have done 表示猜测

　　Need have done 本来需要做的却没有做

　　主从句时间不一致情况下的虚拟语气

　　有时条件从句中的动作和结果与主句中的动作，发生的时间不一致，这时动作的形式应根据它所表示的时间加以调整。如：

　　1. 从句表示将来，主句表示过去：

　　⑴、If I were not to make a preparation for my experiment this afternoon, I would have gone to see the film with you last night.

　　2. 从句表示过去，主句表示将来：

　　⑴、If they had started the early morning yesterday, they would be here now.

　　⑵、If we hadn’ t made adequate preparations, we shouldn’ t dare to do the experiment next week。

　　3.从句表示将来，主句表示现在：

　　⑴、If we shouldn’t have an exam this afternoon, I would go shopping now.

　　4.从句表示现在，主句表示过去

　　If I were you, I would have gone to her birthday party.如果我是你，我就去参加她的生日晚会了。(从句说明现在，主句说明过去。)

　　5.从句表示过去，主句表示过去和现在

　　⑴、If you hadn’t lent me some money, I couldn’t have bought the new house and most likely I would be still living in the dangerous house now.

　　在不少情况下，虚拟式已变成习惯说法，很难找出其暗含的条件。

　　(1) 、You wouldn’t know. 你不会知道。

　　(2) 、 would like to come. 我愿意来。

　　(3) 、I wouldn’t have dreamed of it. 这是我做梦也不会想到的。

　　(4) 、He told the story in such minute detail that he might himself have been an eye-witness. 他将那事讲的非常仔细，简直就象他亲眼看见一样。

　　6.从句表示过去，主句表示现在。

　　⑴、If they had stared the early morning yesterday, they would be here now.

　　⑵、If you had followed my advice, you would be able to finish the work now.

　　希望可以对大家的备考有帮助。预祝各位考生可以顺利备考。