英语中常见从句的简化
简化宾语从句
Su Feng hopes he will be back very soon. = Su Feng hopes to be back very soon.
We decided that we would help him. = We decided to help him.
二、当主句的谓语动词是know, learn, remember, forget, tell等动词，且主句与从句的主语一致时，宾语从句可转换为“疑问词+不定式”结构。如：
She has forgotten how she can open the window.= She has forgotten how to open the window.
当主句的谓语动词是tell, ask, show, teach等动词，且后面带双宾语，从句主语和间接宾语一致时，宾语从句可简化为“疑问词+不定式”结构。如：
Could you tell me how I can get to the station?= Could you tell me how to get to the station?
但是，如果间接宾语与从句的主语不一致时，一般不要把宾语从句简化，否则会产生歧义。如：
He didn’t tell me where he would go. 不能改为 He didn’t tell me where to go.
试理解两个句子的意思。
三、当主句的谓语动词是order, require等时，如果主句与从句的主语不一致，宾语从句可转换为“名词(代词)+不定式”结构。如：
The headmaster ordered that we should start at once.= The headmaster ordered us to start at once.
四、在某些动词后的宾语从句，可以用介词加动名词(短语)等其它形式简化。如：
He insisted that he should go with us. = He insisted on going with us.
The poor boy doesn't know when and where he was born. = The poor boy doesn’t know the time and the place of his birth.
五、某些动词后的宾语从句可转换为“宾语+V.-ing形式(作宾语补足语)”。如：
Liu Ping found that there was a wallet lying on the ground.= Liu Ping found a wallet lying on the ground.
六、动词seem后的宾语从句，也可以用不定式(短语)来转换，但句型要进行适当的变化。如：
It seemed that the boys were going to win. = The boys seemed to win.
除了上述方法外，还有一些特殊句式的转换。如：
I found that it was difficult to learn English well.= I found it difficult to learn English well.
Soon we found that the ground was covered with thick snow.= Soon we found the ground covered with thick snow.
They found that the box was very heavy.= They found the box very heavy.
简化状语从句
在复合句中，常常根据主句和从句的关系把复合句分为名词性从句、副词性从句(即通常所说的状语从句)及形容词性从句(即通常所说的定语从句)。就状语从句而言，有时为了使句子言简意赅，常常将状语从句进行“简化”。
状语从句的“简化”现象常存在于以下五种状语从句中：
①由if, unless, whether等引导的让步状语从句；②由although, though, even if / though, wh-ever等引导的让步状语从句； ③由when, while, as, before, after, until / till, once等引导的时间状语从句； ④由as, as if等引导的方式状语从句； ⑤由as, than等引导的比较状语从句。
下面针对状语从句的“简化”现象归纳讲解。
一、当状语从句的主语是it, 且谓语动词是be时，it和be可完全简化掉。例如：
If (it is) possible, he will help you out of the difficulty.
如果可能的话，他会帮你摆脱困境。
You must attend the meeting on time unless (it is) inconvenient to you.
除非情况对你不便，否则你必须出席这个会议。
二、当状语从句的主语和主句的主语一致时，从句可以将主语和be动词简化掉。常用于以下情形：
1. 连词+形容词
As (he was) young, he learned how to ride a bike.
他小时候就学会了怎样骑自行车。
Whenever (she is) free, she often goes shopping. 她有空就去购物。
Work hard when (you are) young, or you'll regret.
少壮不努力，老大徒伤悲。
2. 连词＋名词
While (he was) a young boy, he was always ready to help others.
他在孩提时代，就乐于助人。
3. 连词+现在分词
As (she was) walking along the river bank, she was singing a pop song.
她沿着河堤边走边唱着流行歌曲。
Although (he is) doing his best in maths these days, he has still got no good marks. 尽管近来他一直在努力学数学，但仍然没有取得好成绩。
4. 连词+过去分词
He won't go there with us unless (he is) invited.
除非受到邀请，否则他是不会和我们一道去那儿的。
The concert was a great success than (it was) expected.
这场音乐会出乎意料地获得了巨大成功。
5. 连词+不定式
He stood up as if (he were) to say something.
他站起来好像要说点什么。
He wouldn't solve the problem even if (he were) to take charge.
即使他来负责也解决不了这个问题。
6. 连词+介词短语
She looked anxious as though (she was) in trouble.
她看上去很焦虑，就好像是遇到了麻烦。
He had mastered the English language before (he was) in the USA.
他到美国之前就精通英语了。
注意：若从句主语和主句主语不一致，从句部分要么用完全形式，要么用独立主格结构来表达。例如：
When the meeting was over, all the people went out of the meeting-place.
当会议结束时，所有的人都走出了会场。(=The meeting over, ...)
简化定语从句
定语从句简化的方法常见的有以下几种：
Ⅰ、把定语从句简化为形容词短语作定语。例如：
She received a box which was full of gifts.
→She received a box full of gifts.
她收到了满满一盒子礼物。
Ⅱ、把定语从句简化为介词短语。例如：
The books which lie under the bed aren‘t worth reading.
→The books under the bed aren‘t worth reading.
床下那些书不值得读。
Ⅲ、把定语从句简化为不定式或不定式短语作定语。例如：
Have you anything that you want to say at the meeting?
→Have you anything to say at the meeting?
你在会上有什么要说的吗？
Ⅳ、把定语从句变成不定式复合结构作定语。例如：
Is there anything else that we can do?
→Is there anything else for us to do?
还有其它我们可做的事吗？
Ⅴ、把定语从句简化成现在分词短语作定语。例如：
The boy who stands against the door is his younger brother.
→The boy standing against the door is his younger brother.
靠门站着的那个男孩是他弟弟。
Ⅵ、把定语从句简化为过去分词短语作定语。例如：
The dictionary which my mother bought for me is very useful.
→The dictionary bought for me by my mother is very useful.
我母亲给我买的那本词典非常有用。
另外：还可以把表明身份、职业等非限定性定语从句简化为同位语结构。例如：
Lao Zhang, who was our hospital driver,died yesterday.
→Lao Zhang, our hospital driver, died yesterday.
老张，我们医院的司机，昨天去世了。
The old man,who is a famous scientist,is coming to give us a report.
→The old man,a famous scientist,is coming to give us a report.
那位老人，一个著名的科学家，要来给我们作报告。