六级英语语法
六级英语语法主要讲的是哪方面的，不管怎么说，基础的语法是逃不过的。下面是本站小编给大家整理的六级英语语法，供大家参阅!
1.先行词为all, anything, something, nothing, everything, much, little, none等不定代词时，关系代词一般只用that，不用which。在大多数情况下that可以省略.
Please tell me everything (that) you know about the matter.
引出的限制性定语从句
在such …as的结构中as可作关系代词，引出限制性定语从句。有时和same连用，在从句中可作主语、宾语或表语等。
Such people as were recommended by him were reliable.
引出的非限制性定语从句
as可作关系代词引出非限制性定语从句，代替整个主句，通常译为“(正)如…一样”，“(正)象…一样”等。as引导的从句一般用逗号与主句隔开，可以位于主句的前面、中间或后面.
I live a long way from work, as you know.
4.分隔式定语从句
定语从句一般紧跟在先行词之后，但有时会被其他句子成分与先行词隔开，从而构成分隔式定语从句。
The days are gone when power politics worked.
5.介词+关系代词(which/whom等)引出的定语从句
如果关系代词(which/whom等)在定语从句中作介词的宾语，那么这个介词可以提到从句前，构成“介词+关系代词(which/whom等)+定语从句”。在这种结构中关系代词不可以用that。
This is a subject about which we might argue for a long while.
6.关系代词在限制性定语从句中常可以省略,一般有以下几种情况：
1) 关系代词在从句中作直接宾语时，在大多数情况下可以省略。
This is something (that) you must always keep in mind.
关系代词作介词宾语时，介词位于句尾时关系代词可以省略;介词位于关系代词之前时则关系代词不能省略。
This is the room (which) Churchill was born in.
2) 关系代词作主语时一般不能省略，但如果关系代词在由there …be存在句构成的定语从句中作主语时常可省略。
This is the only book (that) there is on this subject.
3) 在way后面的定语从句中in which或that通常省略。
That’s the way (that/in which) I look at it.
7.非限制性定语从句
非限制性定语从句修饰先行词或整个主句，起补充说明的作用，如果省略掉，原句句意仍保持完整。非限制性定语从句要用逗号与主句隔开，其引导词不能用that。非限制性定语从句属于正式语体。经常考到的非限制性定语从句有以下三种。
1)由which、as引导的非限制性定语从句。which、as代表整个主句。
He said that he had never seen her before, which was not true.
2)由 “介词+关系代词”引导的非限制性定语从句。
He sent her a letter, in which he said that he was sorry for what he had done to her.
3)由 “数词、代词或名词+of +关系代词”引导的非限制性定语从句。
He had three sons, one of whom was my son’s classmate.
六级英语语法：状语从句1) 时间状语从句
时间状语从句主要由以下连词引导：when, whenever, as, while, since, until, till, before, after, as soon as, once, hardly (scarcely) …when, no sooner …than。
I will discuss the matter with you when we meet tomorrow.
时间状语从句还可由某些可充当连词的名词(the moment, the instant, every time,等)和副词(instantly, directly等)引导：
I will tell you the news the instant I know.
Note:
①before除了可表示“在…之前”外，还可用来强调主句所表达的时间、距离很长或花费的力量相比较大，可译为“…才”。(“not …before”可用来强调主句所表达的时间、距离很短或花费的力量相比较小，可译为“…就”)。
It was a long time before I got to sleep again.
②如果位于when引导的分句之前的主句使用过去进行时、过去完成时或“was/were about to, was/were on the point of”等结构时，when表示突然发生某事，可译为“正在…突然”或“刚…就”等。这时，不能够用as或while来代替when。
I was walking on the street when I ran into my old friend John.
2) 条件状语从句
条件状语从句主要由以下连词引导：if, unless, providing/provided (that), suppose/supposing (that), on condition (that), as/so long as, in case等。
So long as you work hard, you will surely achieve good results in examinations.
3) 让步状语从句
让步状语从句主要由以下连词引导：though, although, even if, even though, whatever, however, whoever, wherever, no matter how/ what/ where/ when等。以下介绍几种较特殊的让步状语从句。
(1)while引导的让步状语从句多放在句首，while相当于although，表示“尽管”，“虽然”。
While I admit I did it, I didn’t intend to.
(2)短语“even now/then/so”相当于“though it is/was true”，表示“尽管如此”，“尽管这样”。
The fire was out, but even so, the smell of smoke was strong.
(3) as引导的让步状语从句要倒装。
Child as he was, he could speak four languages.
4) 比较状语从句
比较状语从句主要由以下连词引导：(not) as …as, (not) the same as, (not) such …as, not so …as, than, the + 比较级…, the +比较级…等。
We have had a lot more rainfall this year than we had last year.
六级英语语法：名词性从句1.什么是名词性从句
在句子中起名词作用的句子叫名词性从句 (Nominal Clauses)。 名词性从句的功能相当于名词词组， 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
2.主语从句
作句子主语的从句叫主语从句。主语从句通常由下列词引导：
1)由what、Whatever、Whoever等代词引导的主语从句： what表示“…所…的(东西)”， 在结构上等于一个名词加一个定语从句; whatever表示“所…的一切”; whoever表示“一切…的人”。例如：
What is hard is to do good all one’s life and never do anything bad。
Whatever was said here must be kept secret。
Whoever fails to see this will make a big blunder。
2)由连词that引起的主语从句： 这类主语从句在大多数情况下都放到句子后部去， 而用代词it做形式上的主语，在口语中连词that有时可以省略掉：
例如：
That we need more equipment is quite obvious。
It doesn’t seem likely that she will be here。
It’s a pity you missed such a fine talk。
3)由连接代词或连接副词how，when，where，why(或whether)引起的主语从句： 这类主语从句， 也可以放到句子后部去， 前面用it做形式上的主语。
例如：
When we shall have our sports meet is still a question。
It is still a question when we shall have our sports meet。
3.宾语从句
名词从句用作宾语的从句叫宾语从句。引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作谓语动词或介词及非谓语动词的宾语。
1)用whether或if引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述句语序。此外，whether与if 在作“是否”的意思讲时在下列情况下一般只能用whether，不用if：
例如：
if与whether都可以与or not连用，但后面紧跟着or not时只能用whether;
We didn't know whether or not she was ready。(此时只能用whether)
I wonder whether/if the news is true or not。(此时则二者都可以用)
后接动词不定式时，用whether;
Can you tell me whether to go or to stay? 你能否告诉我是去还是留?
2) 用that引导的从句作宾语的情形最为普遍， 由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如果从句是并列句时，第二个分句前的that不可省。
例如：
He has told me that he will go to Shanghai tomorrow. 他已经告诉我他明天要去上海。
We must never think (that) we are good in everything while others are good in nothing. 我们决不能认为自己什么都好，别人什么都不好。
注意：在demand、order、suggest、decide、insist, desire, request, command, doubt等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“(should)+ 动词原形”。
3)用who，whom, which, whose, what, when, where, why, how, whoever, whatever, whichever等关联词引导的宾语从句相当于特殊疑问句，应注意句子语序要用陈述语序。
例如：
I just can’t imagine how he could have done such a thing。
Have you decided whom you are to nominate as your candidate。
She will give whoever needs help a warm support. 凡需要帮助的人，她都会给予热情的支持。
以上就是为大家总结的名词性从句中主语从句与表语从句的基本语法知识，考生可以认真掌握，千万不要被绕晕哦!其实名词性从句知识点都多少有点想通，掌握一项的规律，另一项也能相对有所了解，希望大家赶快找到自己学习语法的方法吧!
