天和大家来分享的是英语语法知识当中的主语从句(Subject Clause)， 主语从句即在主从复合句中充当主语成分的句子。对此还不太了解的，今天可以一起来往下看看。 It is important. That we all should attend the meeting is important. It is important (that) we all should attend the meeting. 主语从句的连词 1、连词that(句首不可省略)，whether，if引导的主语从句。 That the earth is round is true. It is true that the earth is round. That you missed such an interesting film is a pity. It is a pity that you missed such an interesting film. That she is still alive is sheer luck. It is sheer luch that she is still alive. It remains unknown whether/if we will go for an outing tomorrow. 注意：whether/if含有“是否”的意思，可以加上“or not”，其语义不变。但如果主语从句位于句首则必从句(Subject Clause)， 主语从句须用连接词whether，不用if。 If the meeting will be put off hasn't been decided yet. (X) Whether the meeting will be put off hasn't been decided yet. (√) It is still a question whether/if it is true or not. Whether it is true or not is still a question. 2、连接代词who，whose，what，which，wh+ever引导的主语从句。 Who will come to teach the students is not known. Whom the watch belongs to is unknown. Whose watch was lost is unknown. Whatever he said wasn't true. 3、连接副词 where，when，how，why引导的主语从句。 Where the library is to be built has not been decided yet. When we start the work is an important question. How this happened is not clear. Why she was late for school is quite clear now. 注意：主语从句中的连词不能重叠使用。 That whether we'll go camping tomorrow depends on the weather. (X) Whether we'll go camping tomorrow depends on the weather. (√) 主语从句的语序 主语从句的语序用陈述语序 When will she come is not known.(X) When she will come is not known. (√) What we need is more time. (√) What do we need is more time.(X) 主语从句的时态 主语从句的时态不受主句时态影响和限制。 What caused the accident remains unknown. What he did yesterday will never be known by his mother. It is certain that he will win the match. It is suggested that the work should be done with great care. 主语从句的注意事项 1. 主语从句的谓语一般用单数形式; When the meeting will be held haven't been known yet.(X) When the meeting will be held hasn't been known yet. (√) When he will come is a puzzle. (√) 2. What引导的主语从句，可根据表语决定主句动词的单复数形式; What he needs is that book. What he needs are some books. 3. What引导的主语从句一般不可以改为含形式主语的句子，that则可以; What you said yesterday is right. It is right what you said yesterday.(X) That she is still alive is certain. It is certain that she is still alive. (√) 4. 常见用it做形式主语的主语从句 It is known to all that the gunpowder was first invented by the Chinese. It is true that he has made a very important discovery in chemistry. It is important that we all should attend the meeting. It is a pity that we won't be able to go to the south to spend our summer vacation. It is doubtful whether she will be able to come. It is said that he has gone to Shanghai. It is still a mystery what caused the accident. It seems obvious that we can not go on like this. 如果你想选择线上英语课来进行培训，大家可以来网校了解了解相关的课程和资讯。如果您对英语学习感兴趣，想要深入学习，可以了解沪江网校精品课程，量身定制高效实用的个性化学习方案，专属督导全程伴学，扫一扫领200畅学卡。

在复合句中作状语的从句叫状语从句。状语从句有时间、地点、原因、目的、结果、条件、方式、比较、让步等共九种状语从句。其中，结果状语从句

1. 有关概念 由一个主句和一个或一个以上从句构成的句子叫做复合句。所谓主句，就是在复合句中起统领作用的句子，它是全句

从句表原因或理由，其关联词有： because,as,since,now (that)等。because,as引导的从句可位于句首,也可位于主句之后；since和now (that)引导的从句一般位于句学到知识。 As the wages were low,there were few applicants for the job.因为工资低,没有什么人申请这份工作。 I can't come tonight,as I'm going to a concert.今晚我不能来,因为我要去听音乐会。 Since we've no money, we can't buy it.由于我们没有钱,我们不能买它。 Now (that) John's arrived,we can begin.既然约翰来了,我们就可以开始了。  2. 下面几种情况只用because：回答why提出的问题；用来引导表语从句；用在强调原因状语从句的强调句之中；当从属连词前有only,just,simply修饰时。 Why is he absent? Because he

句中、主句后，而which引导的非限制性定语从句一般放于主句后或句中。 ②as常与从句中的know，see， hear，expect等动词连用，也常用于as often happens，as is often the case（常从句修饰先行词，对先行词起修饰作用，不同引导词有不同的含义和用法，下面，小编就来给大家分享一下选择定语从句有的事）等句子中；而which一般不用于以上情况。 ③as有“正如”的含义，which没有此含义。如： As is well known，Shanghai is a big city． Some of the roads were flooded， which made our journey more difficult．   关系代词who

句话都不会有语法错误，这就是同位语。同位语的部分变成一个句子的形式就生成了相应的从句叫做同位语从句。同位语从句出现在句子中名从句 先看下面两个句子： 第一个：It is a question。 第二个：The discussion is whether the book is worth reading。 这两个句词性成分之后，这个名词一般是专有名词或比较抽象的概念，比如说：fact(事实)、idea(想法)、theory(理论)、assumption(假设)等等，后面常出现由that引导的同位语从句。常用来引导同位语从句的引导词主要包括：that、whether等。

名词性从句可以称作为主语从句，主语从句就是用来做句子的主语的。主语从句

管你说什么都令我们感兴趣。 Whenever you come is OK．你无论何时来都行。 和whether的选用 引导主语从句，不从句是一个重要的语法点，主语从句能用if，只能用whether。 如： Whether we will hold a party in the open air tomorrow depends on the weather. 我们明天是否在户外开晚会要看天气而定。

定语从句

到了一个更好的学习环境。（结果状语从句） 2.目的状语从句常常使用can，may，will，could, might, would, should等情态动词。结果状语从句则用陈述语气来表达，从句中通常没有情态动词。 eg.I always read so carefully that I can make everyone understand me.     我总是小心翼翼地读书，这样大家就都能懂了。（目的状语从句）     I always read so carefully that I make everyone understand me.     我总是小心翼翼地读书，结果大家全都理从句又可以引导结果状语从句解了我讲的话。（结果状语从句） 3.目的状语从句与主句的关系紧密，而结果状语从句则是句子的多余补充，原本句子意思已经完整，结果状语再进行一个内容的添加。 eg.We all prepared well，so that the party began .     我们都准备好了，结果舞会就开始了。（结果状语从句）     We’ll prepare well so that the party can begin.     我们要好好准备，以便开始舞会。（目的状语从句） 4.目的状语从句放在句首对目的进行重点强调，而结果状语从句只能置于主句之后，作为前面动作的后续补充。 eg. So that we might see the sunrise， we started for the peak early．       为了看日出，我们一早就去山顶。（目的状语从句）      We started for the peak early，that we saw the sunrise. (结果状语从句)      我们一早就去了山顶，结果看到了日出。 以上就是小编为大家整理的目的状语从句和结果状语从句的四大区别，大家都记住了吗？ 其实这两者最大的区别就是一个事实一个是虚拟，只要把握了这一点，然后再结合整体语境理解句意，相信大多数题目都难不到你了！