得到同样的结果。   2．原因状语从句： 原因状语从句多由because，as，since，seeing(that)，considering that等连词引起： You only do it because you have to． 你这样做只是因为不得不如此。 As he had been up since 4 a.m.，he was very tired． 由于他清晨四点就起床了，他十分疲倦。 He can’t come with us since he’s ill. 由于生病他不能和我们一道去。 Stay in bed longer today，seeing that you were late last night. 昨夜你睡得晚，你今天多睡一会儿。 Considering he’s only been learning English a year he speaks it very well. 考虑他学英语才一年，他英语是讲得很好的。 Now that you have the chance you had better avail yourself of it. 既然你现从句 地点状语从句在有了机会，你最好加以利用。 下面这类句子中的从句也表示原因： I’m glad that you are all safe． 我很高兴你们都安然无恙。 I’m proud that you had the thought． 你有这个想法我感到骄傲。

从句是英语语法中的一个重要结构，它用于对句

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。

关系副词when引导定语从句，从句的现行词一般都是表示时间的名词。此时，关系副词when在定语从句中作时间状语。When的含义有时候相当于"介词+which"，因此常常跟"介词+which"交替使用。下面和小编一起详细了解一下关系副词when引导的定语从句的具体用法吧！ When引导限定性定语从句是对先行词进行修饰限定，在语法功能上就是一个定语。 例句1：There are occasions when (on which) one must yield. 任何人都有不得不屈服的时候。 例句2：I will never forget the days when (in which) we shared all the roses and thorns. 我永远都不会忘记我们在一起同甘共苦的日子。 关系副词when引导非限定性定语从句 When引导非限定性定语从句时对先行词的补充说明，在语法功能上其实相当于补语。 例句1：It was on Mid-Autumn Festival, when all family members reunite, that I left my hometown for a strange city alone. 正是在中秋节这个家人团圆的日子，我却独自离开家乡去了一个陌生的城市。 注释：when在这里引导非限定性定语从句，并在从句中充当状语，这里也可以用on which代替。 关系副词when引导定语从句时的模糊化 在when引导定语从句时，大多数时候定语从句的先行词都是比较明显的时间词，比如：time, year, month等。但是，有一些抽象的先行词具有模糊时间概念的，比如：stay, visit, occasion, interval, moment, span, age等。此时，如果定语从句需要用关系副词连接，同样也用when。 例句1：I will brand my golden stay in Paris on my heart when I led a happy and fruitful life.  我会将我在巴黎那段幸福而有收获的日子铭记于心。 注释：此时先行词stay就是一个具有模糊时间概念的先行词，when在定语从句中充当时间状语，相当于during which。 例句2：At the age when other people retire, Francis began the greatest cause in his life. 在一个别人退休的年龄，弗朗西斯开始了他一生中最伟大的事业。 注释：此时age是一个具有模糊概念的先行词，when在定语从句中充当时间状语，相当于in which） 通过上述分析我们可以了解到when引导的定语从句在高考中常考的内容就是先行词的模糊化，也是难度相对较大的考察方向。所以，小编建议大家在学习的过程中对于这些较模糊的先行词要多积累，多运用，以留下深刻的映像并形成习惯。

不能省略；what 在从句中可作主语、宾语、表语等，不能省略。如： Mary is no longer what she used to be．玛丽不再是从前那样了。（what在表语从句中作表语） The question is what we should do to prevent him from going．问题是我们怎样做才能阻止他去。（what在表语从句中作动词do的宾语） The reason why he didn’t come today is that his mother is ill．他今天没来的原因是他母亲病了。（that只起连接作用） 四、引导同位语从句 that与what都可引导同位语从句修饰表示抽象概念的名词，对所修饰的名词的具体内容进行详细阐述。这类名词有：fact, idea, news, hope, belief, promise, thought, suggestion, proposal等。that在从句中不作句子成分，但不能省略。what 在从句中可作主语、宾语、表语等，不能省略。如： I have no idea what we should do next．我不知道我们下一步该做什么。（宾语） He made a promise that he would study hard．他许诺要努力学习。(that只起连接作用) The boy expressed his hope that he would be a pilot when he grows up．那个男孩儿表达了他长大后想当一名飞行员的愿望。（that只起连接作用） 五、引导定语从句 that可引导定语从句且在定语从句中作主语或宾语，that既可指人也可指物。that在从句中作宾语时可省略。如： This is one of the buildings that were built last year．这是去年建的楼房之一。（that在定语从句中作主语，指物，不能省略。） The doctor that you met in the street yesterday came here 20 years ago．你昨天在街上遇到的那位医生二十年前就来到这里了。（that 在从句中作宾语，指人并可省略。） 注意：what不能引导定语从句。如不能说： 1．He did all what he could to save the patient． 2．All what he needs is more time． 应将句中的what改为that，或去掉what，还可以将以上两句中的all去掉，但两句的结构发生了根本的改变：句1中的what引导宾语从句，句2中的what引导主语从句。 六、引导状语从句 so．．．that, such ..．that, so that结构引导状语从句。what不能引导状语从句，但whatever, no matter what可引导让步状语从句。如： He made such rapid progress in English that before long he could write articles for an American newspaper．他的英语进步很快，不久就能为美国的一家报社写文章了。 Put the little plants in the shade so that the sun won’t burn them．请把幼苗放在阴凉处从句 that与what都可引导主语从句，that在从句中不作句子成分，但不能省略。what 在从句以免太阳晒枯它们。 Don’t believe him no matter what he says．无论他说什么，都不要相信他。

定语从句和同位语从句之间有很多“扑朔迷离”关系。很多学习英语的同学们经常会把两者混淆，导致学习英语时，常常迷惑。小编为大家整从句和同位语从句理了若干有关定语从句和同位语从句的区别，一起来看看吧！ 和先行词的关系不同。同位语从句说明先行词的具体内容，二者是同位关系;定语从句修饰限定先行词，二者是修饰关系。 The news that he told me is that Tom would go abroad next year. 他告诉我的消息是汤姆明年将出国. (第一个that引导的从句是定语从句,that在从句中作宾语) The news that Tom would go abroad is told

1．定义：    用作同位语的从句叫做同位语从句。 2.用法：    同位语从句的先行词多为fact, news, idea, thought, question, reply, report, remark等，关联词多用从属连词。    如： They were all very much worried over the fact that you were sick.    注：   同位语从句偶尔由从属连词whether引导。    如：I have no idea whether he’ll come or not.我不知道他是否来。    连接代词who, which, what

从句最常用的连词是if,由if引导的条件状语从句早点动身，你就不能及时赶到那儿。 Unless it rains,the game will be played.除非下雨，比赛将照常进行。 2、on condition(that)...在……条件下，如果 on condition (that)...引导的条件从句是主句事件发生的前提条件或唯一条件。 I can tell you the truth on condition that you promise to keep a secret.我可以告诉你真相，条件是你答应保密。 You can go swimming on condition (that) you don't go too far from the river bank.你只有在不远离河岸的条件下才可以下水游泳。 3、supposing conj.如果，假如 supposing引导的条件从句表示一种假设条件。 Supposing it rains,shall we continue the sports meeting?倘若下雨，我们的运动会还要继续举行吗? Supposing anything should go

从句 1）主语从句可直接位于主语的位置，如果从句较长，谓语又较短，可用it作形式主语，而将从句放在句末。常见的句

用来判断。 时间状语从句：表达时间的状语，常由when, while, before, after, since等引导。 例句：She called me when she arrived.（她到达后给我打电话。） 地点状语从句：表达地点的状语，常由where, wherever等引导。 例句：I will go wherever you go.（我会到你去的任何地方。） 原因状语从句：表达原因的状语，常由because, since, as等引导。 例句：He failed the exam because he didn’t study.（他考试不及格是因为没学习。） 条件状语从句：表达条件的状语，常由if, unless, provided that等引导。 例句：If it rains, we will stay at home.（如果下雨的话，我们会呆在家里。） 通过本文的介绍，相信读者已对英语中不同类型的从句的判断方法有了更加清晰的认识。掌握正确的判断技巧和思路，可以帮助学习者更准确地从句类型的判断方法对于正确理解句理解和运用从句，提高语法分析和句子理解的能力。希望本文所提供的方法能够帮助读者更好地掌握从句类型的判断，为英语学习和交流打下坚实的基础。   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。