1. be doing/be about to do/had done…when…(when：这时, 强调一个动作的突然发生)
I was walking along the river when I heard a drowning boy cry for help.
I was about to leave when it began to rain.
I had just finished my test paper when the bell rang, announcing the exam was over.
2. It was (not ) + 时间段+before +一般过去时（过了一段时间就......）
It will (not ) be+ 时间段+before +一般现在时（要过一段时间才会…）
It is/has been +时间段+ since…..
It was +点时间+ when…..
It was +时间状语+ that …..（强调句）
It was not long before he sensed the danger of the position.不久他就意识到他处境危险（动作已发生）
It will be half a year before you graduate from the school. 还有半年你才从这个学校毕业（动作未发生）
It is 3 years since he worked here.
It was 3 o’clock when they received the telephone.（时间状语从句）
It was at 3 o’clock that they received the telephone.
3. more…than… 与其说…倒不如…(= not as/ so……..as……)
more than=not only 不仅仅……..
It is more like a meeting than like a party.
Mr. Zhang is more than my teacher, he is also my best friend.
4. once… 一旦…...
Once you understand what the teacher explained, you will have no difficulty doing the work.
Once you have decided to do something, you should finish it and do it well.
5. The +比较级…，the +比较级… 越……, 越……
The more books you read, the more knowledge you will get.
The busier he is, the happier he feels.
6. as if/ as though… 好像...（表示与事实相反，用虚拟；若表示即将成为事实或有可能成为事实，则用陈述语气。）
He was in great trouble, but he acted as if nothing had happened.
Although they just met for the first time, they talked as if they had been friends for many years.
The clouds are gathering. It looks as if it is going to rain.
7. n./adj./adv./v. + as/though +主语+谓语，尽管...，引导让步状语从句。
Child as he is, I already know what career I want to follow.
Try as he might, he couldn’t solve the problem.
Much as I respect him, I can’t agree with his idea.
8. whether….or…. 无论…还是…
Whether the weather is good or bad, they will set off as they planned.
Any person, whether young or old, has his own worth.
9. 特殊疑问词+ever = no matter+特殊疑问词, 引导让步状语从句或名词性从句。
Whichever(=No matter which) you like, you can take it away.( 让步状语从句)
You can take away whichever(=any one that) you like.(宾语从句)
Whoever breaks the law, he will certainly be punished. ( 让步状语从句)
Whoever breaks the law will certainly be punished. ( 名词性从句)
10. if/as long as/so long as/ providing that/ provided that/ supposing that/on condition that 如果/只要/假如…
I will lend you money on condition that you can return it within 3 months.
11.given that/ considering that 考虑到….., 鉴于……
Given her interest in children/Given that she is interested in children, I’m sure teaching is the right career for her.
12. in case that/ in case of… 万一…
In case of fire, please dial 119 at once.
In case that John comes/John should come, tell him to wait.
13. 祈使句+ or/otherwise +结果句；祈使句+ and +结果句
Stop doing such foolish thing, or you will be punished in time.
More effort, and the problem would have been settled.
Think it over, and you will find the answer.
14. so/ such……..that…….引导结果状语从句，须注意当名词前有many, much, little, few修饰时, 用so不用such。
The westerners eat so much fat and sugar that they put on weight easily.
There are so few fish in the lake that we couldn’t fish them easily.
当主从句主语一致时可与动词不定式相互转换,即变成so/such…….as to do结构。
The westerners eat so much fat and sugar as to put on weight easily.
15. so that 引导目的状语从句与结果状语从句
so that引导目的状语从句时常与情态动词连用（= in order that）。
He turned up the radio a little so that he could hear the news clearly.
He turned up the radio a little so as to hear the news clearly.
16.can never/can’t 与too, too much, enough, over- 搭配表示“无论怎样…都不过分”
While you are doing your homework, you can’t be careful enough.
He is such a great man that we can’t praise him too much.
William Hartley was handsome, determined and hardworking. In a word, I couldn’t speak too highly of him.
The development of society has made it necessary for us to have a good knowledge of English, so we can’t overemphasize the importance of learning English.
Since it is a good thing, we can’t do it too soon.
It +系动词+adj./n.+ for sb. to do (sb.表示动词不定式动作的执行者)
It +系动词+adj.+ of sb. to do （sb.既表示动词不定式动作的执行者，又表示人所具备的性质或特征）
It’s important for us to have a good knowledge of English.
How rude of him to treat a child like that!
It’s thoughtful of him to fix us up for the night.
主语+think/consider/believe/ make/ feel+ it +adj./n. +for sb./ of sb. +to do sth.
I feel it foolish of him to believe such a man.
The timely rain had made it possible for the crops to grow well.
19. won’t/ can’t have sb. doing/done 不能容忍某行为发生
You are too rude, and I won’t have you speaking to Mother like that again.
We can’t have anything done against the school rules.
20. It is said/thought/ hoped/ believed...that...=sb. is said/thought/hoped/believed to do…..
He is said to be studying abroad.
It is considered that many countries highly value China’s role in helping world’s peace.=Many countries is considered to highly value China’s role in helping world’s peace.
21. had hoped to do=hoped to have done表示过去原打算干却未曾实现的愿望、打算或意图。类似的动词还有：expect, think, intend, design, plan, mean, suppose等。
I had hoped to travel to London this summer，but I was too busy.
22. How did sb come to do...? = How come that….为什么会…../……是怎么回事？表示要求对所发生的事情说明理由或做出解释。
How did you come to find out where she’s living?= How come that you found out….
How come that you sat there ,doing nothing?为什么坐在那儿什么也不干?
23. It is (not ) like sb. to do… ...（不）像某人的所作所为
It’s like him to answer for what he has done.敢对自己的行为负责，这是他的一贯作风。
It’s not like him to have been so rude to his mother.
24. when it comes to… 当谈到或涉及到…
He is a man of few words, but when it comes to playing computer, he will be excited and full of energy.
When it comes to helping his wife with the housework, John never complains.
25. every time/ each time/ next time/ the first time/ any time等短语引导时间状语从句，表示“...次的时候”。
Every time you meet with new words while reading, don’t always refer to your dictionary.
Next time you come , do remember to bring your son here.
You are welcome to come back any time you want to.
26. There is (no) need to do…/for...=It is ( not ) necessary for sb. to do…
There is ( no ) hope/chance/possibility of doing…
There is( no )difficulty/trouble/point/delay( in )doing...
Is there any chance of us/our winning the match?
There is no point（意义）in discussing the problem again.
27. It is up to sb. to do sth. 应由某人来做某事……..
——When shall we start out?
——It’s up to you to decide.
It’s up to you to babysit my so while I am away on business.
28.be up to sth. 忙于…..., 从事…..., 胜任.…..
John isn’t really up to that job. 约翰不适合干那项工作。
What have you been up to recently? 最近你一直在忙些什么？
29. It is time to do/It is time that +主语+动词的一般过去式 该是做…..的时候了
It is time that we ended the discussion.
30. 强调句基本构成形式：It is/ was +被强调部分+ who/that+原句剩余部分
I met him in the street yesterday afternoon.
It was I who/ that met him in the street yesterday afternoon.(强调是我，不是别人)
It was him who/that I met in the street yesterday afternoon.( 强调我遇见的是他，不是别人)
It was in the street that I met him yesterday afternoon.( 强调是在大街上，不是在别的地方，强调的是地点，但不用where)
It was yesterday afternoon that I met him in the street (强调是昨天下午，不是在别的时候, 强调的是时间，但不用when)