语法: 复合句
英语句子按其结构可以分为三类：简单句、并列句和复合句。
复合句（Complex Sentences）：包含一个主句和一个或几个从句的句子叫复合句。复合句按其在句中充当的成分又分成名词性从句、形容词性从句和副词性从句。
一、名词性从句：包括主语从句、表语从句、宾语从句和同位语从句。
1. 主语从句 (Subject Clause)：从句在句中作主语叫主语从句。引导主语从句的连词叫连接代词、
连接副词和连词。
1).连接代词：能在主语从句中作主语、宾语、表语、定语的连词叫连接代词。
它包括：who, whom, whose, what, which, whoever, whomever, whatever,whichever
How the book will sell depends on its author. 书销售如何取决于作者本人。
It is still unknown which team will win the match.哪对将赢得这场比赛还不确定。
2).连接副词：能在主语从句中作状语的连词叫连接副词，它包括：when, where, why, how
When shall go there is not clear. 什么时候去那里还不清楚。
3).连词：在主语从句中只起连接作用，它包括：that, whether, if
Whether the plan is feasible remains to be proved.这一计划是否可行还有等证实。
2. 表语从句 ()：从句在句中作表语叫表语从句。
1).连接代词：能在表语从句中作主语、宾语、表语、定语的连词叫连接代词。
它包括：who, whom, whose, what, which, whoever, whomever, whatever,whichever
That is what we should do first. 那就是我们首先应该做的事。
2).连接副词：能在表语从句中作状语的连词叫连接副词。它包括：when, where, why, how,because
That is where you are mistaken. 那就是你出错的地方。
3).连词：在表语从句中只起连接作用。它包括：that, whether, as if (as though)
The point is whether we should lend him themoney. 问题在于我们是否应该借钱给他。
3. 宾语从句 (Object Clause)：从句在句中作宾语叫宾语从句。
1).连接代词：能在宾语从句中作主语、宾语、表语、定语的连词叫连接代词。
它包括：who, whom, whose, what, which, whoever, whomever, whatever,whichever
I take back what I said. 我收回我说我的话。
2).连接副词：能在宾语从句中作状语的连词叫连接副词，它包括：when, where, why, how
Our success depends on how well we can cooperate with oneanother.
我们成功取决于我们互相之间合作得如何。
3).连词：在宾语从句中只起连接作用，它包括：that, whether, if
Let us know whether / if you can finish the article beforeFriday.
请让我们知道你是否能在星期五以前把文章写完。
4. 同位语从句：从句在句中作同位语叫同位语从句。
1).连接代词：能在同位语从句中作主语、宾语、表语、定语的连词叫连接代词。
它包括：who, whom, whose, what, which, whoever, whomever, whatever,whichever
The problem who should be our headmaster is not decided.谁当我们校长这个问题还没有确定。
2).连接副词：能在同位语从句中作状语的连词叫连接副词，它包括：when, where, why, how
I have no idea when he will return. 我不知道他什么时候回来。
3).连词：在同位语从句中只起连接作用，它包括：that, whether
I just got word that he is not coming this evening.我刚获得消息他今晚不来了。
二、形容词性从句：即定语从句。定语从句根据连词在句中充当的成分分为关系代词和关系副词两种。
1. 关系代词：能在定语句中作主语、宾语、表语、定语的连词叫关系代词，
它包括：who,whom, whose, which, that, as (the same…as, such…as)
1).The girl who is standing there is Mary. 站在那里的女孩是玛丽。(主语)
2).He is the man (who) I saw in the park yesterday. 他就是我昨天在公园里见到的那个人。(宾语)
3).Beijing is not the city (that) it was. 北京不是以前那个样子了。(表语)
4).He borrowed a book whose auther was a peasant.
=He borroweda book the auther of which was a peasant.
=He borroweda book of which the auther was a peasant.
我借了一本书，书的作者是个农民。(定语)
2. 关系副词：能在定语从句中作状语的连词叫关系副词，它包括：when, where, why, how
1).I still remember the day when he was killed.
= I still remember the day on which he was killed.我还记得他被害的那一天。(时间状语)
2).This is the factory where he works.
= This is the factory in which heworks. 这就是他工作的工厂。(地点状语)
3).Do you know the reason why she was late?
= Do you know the reason for which she waslate? 你知道他迟到的原因吗？(原因状语)
4).That was the way (how) the nurse looked afterus. 护士就是这样照顾我们的。(方式状语)
三、副词性从句：即状语从句。它包括：
1.时间状语从句 (when, while, as, as soon as, once, immediately, themoment/instant/second,
the day/week/month/year, last/nexttime, the first/second… time, by the time)
The film had begun when we got to the cinema. 我们到达电影院的时候，电影已经开演了。
2.地点状语从句 (where, wherever, everywhere)
There is a city where there is ariver. 有河的地方通常就有一个城市。
3.原因状语从句 (because, since, as)
Because he was ill, I didn’t go toschool yesterday. 他病了，所以昨天没来上学。
4.条件状语从句 (if, unless, as/so long as, suppose/supposing)
If it rains tomorrow, we won’t gothere. 如果明天下雨，我们就不去那里了。
5.目的状语从句 (so that, in order that)
We must work hard so that we can go tocollege. 为了上大学我们必须努力学习。
6.结果状语从句 (so…that, such…that, so that)
He is so good that we all like him.他非常好，我们都喜欢他。
7.方式状语从句 (as, like, as if, as though)
Do as you like. 做你喜欢做的事。
8.比较状语从句 (as…as, than)
This book is as interesting as thatone. 这本书和那本书一样有趣。
9.让步状语从句 (though, although, while, when, as, even if, eventhough, whether, whether…
or, whoever (whomever, …), no matterwho (whom,…)
Though he is a child, he knows a lot.他虽是个孩子，但他知道很多。
