高考英语语法讲解——主从复合句（附练习题）复合句由一个主句和一个或一个以上的从句构成的句子叫复合句。
在复合句中主句是全句的主体，从句是全句的一个成分，不能独立。
从句有：名词性从句（主语从句，表语从句，宾语从句和同位语从句）状语从句定语从句（详细请看以下内容）II.状语从句状语从句是每年高考必考的内容，在高考试题中加上其它从句的干扰，以及倒装句，强调句的介入，使得状语从句更为复杂。
1.时间状语从句由下列连词引导：when，while，as，before，after，once，till，until，since，as soon as，now that，hardly…when，scarcely…when，no sooner…than，有一些表示时间的副词（短语）或名词短语也可引导时间状语从句。
如：directly，instantly，immediately，by the time，the moment，the second，the minute，the instant，every time，each time，next time，the last time等重点内容如下：①when，while，as引导的时间状语从句▲as表示“当……的时候”，往往和when/ while通用，但它着重强调主句与从句的动作或事情同时或几乎同时发生。
She came up as I was cooking.（同时）The runners started as the gun went off.（几乎同时）▲when（at or during the time that ）既可以表示在某一点的时候，又可表示在某一段时间内，主句与从句的动作或事情可以同时发生也可以先后发生。
It was raining when we arrived.（指时间点）When we were at school， we went to the library every day.（在一段时间内）When we arrived there，the film had already begun.（先后发生）▲while意思是“当……的时候”或“在某一段时间里”。
主句中的动作或事情在从句中的动作或事情的进展过程中发生，从句中的动词一般要用延续性动词。
在when表示a period of time时，两者可以互换。
Please don’t talk so loud while/when others are working.He fell asleep while/when reading.Strike while the iron is hot.（不可用as或when，这里的while意思是“趁……”）②before状语从句的重点句型▲……之后……才：It was a long time before I got to sleep .▲不多久……就：It wasn’t long before he told me about the affair.▲不等……就：Before I could get in a word， he had measured me.▲刚……就：He hardly entered the room before he heard the telephone ring.▲先……再：You can have a few days to think about it before you make your decision.③since 引导的从句用延续性动词的过去式（包括过去完成时），则从句的动作已经结束，从句意思是否定的。
如果从句的动词是延续性的用完成时态，从句意思是肯定的。
▲He has never been to see me since I was ill.我病愈后，他一直未来看我。
（不在生病了）▲He has never been to see me since I have been ill.我病了，他一直未来看我。
▲I haven’t heard from him since he lived here.自从他这里搬走，我就没有收到他的信。
（不住在这儿了）▲I know him very well since he has lived here near us.自他住在我们附近以来，我对他很了解。
▲It’s three years since I was in the army.我退伍已三年了。
（不在服役了）▲It’s three years since I have been in the army＝It's three years since he joined the army.我入伍已三年了。
④如果与till与until从句使用的主句是肯定的，则主句中谓语要用延续性动词如果与其使用的主句是否肯定的，则主句中谓语要用短暂性动词。
另till从句不可以置于句首，只有until从句可以放在句首。
not until 放在句首时主句要倒装。
2.原因状语从句由下列连词引导：as（由于），because（因为）， since（既然），now （that）（既然）， considering that（顾及到）， seeing that（由于）。
I do it because I like it.因为我喜欢我才干。
（because不能与 so 连用）He couldn’t have seen me， because I was not there.他不可能见过我，因为当时我不在那儿。
Seeing （that） quite a few people were absent， we decided to put the meeting off.由于好些人都没到会，我们决定延期开会Now that/Since you are all here， let’s try and reach a decision.既然大家都来了咱们就设法做一个决定吧As she was ill， she didn’t come to the party.由于病了，她没来参加晚会。
Considering that they are just beginners， they are doing quite a good job.考虑到他们才刚刚学做，他们干得算很不错的了。
重点内容如下：①because语气最强，用于回答why的提问，可与强调词only，just 以及否定词not 连用。
但不可以与so连用。
如You shouldn’t get angry just because some people speak ill of you.另外注意与not连用时否定的转移。
He didn’t do such a thing because he was afraid of his wife.他并不是因为怕他的妻子才做这样的事。
Cf：He didn’t do such a thing，because he was afraid of his wife.因为怕妻子，他没有做这样的事。
because引导的从句可以被强调：It was because she wanted to study abroad that she entered for TOEFL②as语气较弱，since语气也较弱，但比as正式一些，所说明的原因比较明显或是已知的事实，多用于口语中，所以不应该强调。
常置于句首。
As all the seats were full，he stood there.Since you are going，I’ll go，too.③for虽解释为“因为”但只是一个并列连词，它引导的是并列句，不是原因状语从句。
The day was short，for it was December.3.地点状语从句由下列连词引导：where，wherever，anywhere，everywhere。
Anywhere he went，he got warm welcome.The girl takes the doll with her everywhere she goes.Wuhan lies where the Yangtze and the Han River meet.武汉位于长江和汉水汇合处。
Where there is a will， there is a way.有志者，事竟成。
You’d better make a mark where you have any questions.哪儿有问题，你最好在哪儿做个记号。
（这里where引导的从句不是定语从句）4.结果状语从句由下列连词引导：that，so…that，so that（从句中不带情态动词），such…that，with the result that等。
注意以下几种结构：①so＋adj/adv＋that…②such（a/an＋adj）＋n＋that…③so＋adj＋a/an＋n＋that＝such a/an＋adj＋n＋that…④so many/much/few/little（少）＋n＋that…注意以上结构与定语从句so/such…as的区别。
This is such an interesting/so interesting a film that/as everyone wants to see it/（it）.He didn’t plan his time well so that/so he didn’t finish the work in time.他没把时间计划好，结果没按时完成这项工作。
We left in such a hurry that we forgot to lock the door.我们走得匆忙，把门都忘了锁了。
The village is so small that it cannot be shown in the map.这村子太小，所以这地图上没有。
Jenny is such a clever girl that all the teachers like her very much ＝ Jenny is so clever a girl that all the teachers like her very muchJenny是如此聪明的女孩，以至老师们都非常喜欢她。
I have had so many falls that I am black and blue all over.我摔了许多跤，以至于浑身青一块紫一块He has so few friends that he often feels lonely.他朋友很少，所以经常感到孤独。