loading“情态动词+have done”表推测一览表
情态动词+ have done must have done can’t have done could have done 用法 一定已经做了 不可能已经做了 例句 They must have finished their work. They can’t have finished their work 可能已经做了或本来可You could have used my computer because I didn’t use it. 能做但未做 may have done might have done 也许已经做了 They may have finished their work. 也许已经做了或本来可You might have used my computer because I didn’t use it. 以做但未做 Should/ought to have done need not have done would rather have done would like to have done had better have done 本来该做但未做 本来不必做但做了 过去宁愿做但未做 过去想做但未做 当时最好做了某事 You Should have studied hard. You need not have gone out. I would rather not have gone there. I would like to have seen the film. You’t better have gone there. “情态动词+be doing”表推测一览表
情态动词+ be doing must be doing can’t be doing May/might be doing 用法 一定正在做 不可能正在做 也许正在做 例句 They must be watching TV now. They can’t be watching TV now. They may be watching TV now. 口诀：“情动”加上have done,推测事情已经干； “情动”加上be doing,推测事情在进行；
条件状语从句中的虚拟语气：条件句分为真实条件句和虚拟条件句两种，真实条件句用陈述语气，
虚拟条件句用虚拟语气。（虚拟条件句是虚拟语气的重点）
虚拟条件句关键是要熟练掌握以下三大公式：
三个相反 与现在事实相反 与过去事实相反 与将来事实相反 从句 主句 If sb did/were… If sb had done… If sb did/were… If sb were to do… If sb should do… Sb would/should/could/might do… Sb would/should/could/might have done/have been… Sb would/should/could/might do…
1、宾语从句中的虚拟语气：有三种情况。
一是在动词insist(坚持)，order（命令），command(命令)，suggest（建议），advise（建议）。
Recommend（建议，推荐），require（要求）,request（请求），demand（要求），desire（要求，
愿望），等动词后面的宾语从句中一般用虚拟语气，其结构为“主语+should+动词原形”，其中
should可以省略。
把以上10个动词简称为：一个“坚持”，两个“命令”，三个“建议”，四个“要求”。 二是动词wish之后接宾语从句一定要用虚拟语气。 从句的时态是：
1、与过去事实相反用had done/had been, 2、与现在事实相反用did或were,
3、与将来事实相反用“would/might/could/should+动词原形”。
注意：wish在简单句中并非表示的是虚拟语气，如：wish you success.祝你成功。
三是在would rather的宾语从句中，也要使用虚拟语气，其从句中谓语动词的时态用一般过去时。如：I would rather you didn’t hear what I said. 我宁愿你没有听到我说的话。
2、主语从句中的虚拟语气
少数“it is+形容词+that+主语+should+动词原形”，其中should同样可以省略。常见形容词有：important,necessary,strange,unusual,curious,remarkable,surprising,desirable,natural等。
3、定语从句中的虚拟语气
“it is(high/about) time that+主语+动词的过去式，或者是“should+动词原形”。Time
是先行词，that是引导词，其意思是“早该做什么事了”
如：1、It is high time that you went to school.=it is high time that you should go to school.你该上学了。
2、It is about time that you picked up your daughter at school.= It is about time that you should pick up your daughter at school.你该去学校接你女儿了。
熟练掌握强调句型：句型结构是：it is/was+被强调部分+that/who+句子原有部分。在强调句型中，强调人时，一般用who,也可用that,但强调时间，地点等时只能用that,不能用when,where等。
1、 2、 3、 4、
强调主语 强调地点状语 强调时间状语 强调宾语。
not …until…的三大句型：
例：妈妈回家之后我才睡觉。
正常 I did not go to bed until my mother come back home. 强调 It was not until my mother came back home that I went to bed. 倒装 Not until my mother came back home did I go to bed.
怎样识别not …until…是强调句还是倒装句呢？很简单，如果否定词not在句首，就是倒装
句，如果it在句首，就是强调句。
it的10大句型
1、It was for the first time that I wrote to a foreign pen friend.这确实是我第一次给一个外
国笔友写信。
这是强调句型。还原为：
I wrote to a foreign pen friend for the first time.
2、It is the first time that I have written to a foreign pen friend. 这是我第一次给一个外国
笔友写信
这是定语从句，that之后的时态要用现在完成时态。
3、It was eight when the class began.8点钟开始上课。
这是时间状语从句，强调句型：
It was at eight that the class began.
4、It is possible that I will enter this key university.我上这所重点大学是可能的。
这是主语从句。It是形式主语。that I will enter this key university是真正主语。还原成：
That I will enter this key university is possible.
5、It is/has been three years since he got married.他结婚（成家）已经三年了。
It is/has been some time since sb did(短暂性动词)sth.意为“自从某人干某事已经有多长时
间”例如：
It is/has been three years since he worked here.他不在这儿工作已经三年了。
6、It will be one year before she finishes middle school.再有一年时间她就中学毕业了。 It is/was/ will be some time before…意为“过多长时间后再干什么”。 7、It is high time we went to school.我们上学的时间到了。
这时定语从句，在It is（high）time that…句型中，that之后谓语动词的时态要用一般过去