名词性从句复习.doc

名词性从句在句子中起名词作用的句子叫名词性从句。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,名词从句又可分为主语从句、宾语从句、表语从句和同位语从句。主语从句的用法一. 主语从句在复合句中作主语, 它可以位于句首, 但常见的主语从句多放在句末,句首则用形式主语it。1. That the earth is round is true. = It is true that the earth is round. 2. Whether he will come hasnt been decided. = It hasnt been decided whether he will come. 注意: 连词that, whether在从句中不担任句子成分,只起连接作用,不能省略 (注:if不可用来引导主语从句）二. 用it 作形式主语的结构(1) It is名词从句 It is a fact that 事实是 It is an honor that 非常荣幸 It is common knowledge that是常识(2) It is形容词从句 (多用 should) It is natural that 很自然 It is strange that 奇怪的是(3) It is 不及物动词从句 It seems that 似乎 It happened that 碰巧 It appears that 似乎(4) It is过去分词从句 It is reported that 据报道 It has been proved that 已证实 It is said that 据说 it 作形式主语和it引导强调句的比较 it 作形式主语代替主语从句,主要是为了平衡句子结构, 主语从句的连接词有变化。而it引导的强调句则是对句子某一部分进行强调,无论强调的是什么成分,都可用连词that。被强调部分指人是也可用who/whom。例如:判断: It is a pity that you didnt go to see the film. It doesnt interest me whether you succeed or not. It is in the morning that the murder took place.It is John that broke the window宾语从句的用法：句子结构：主句 + 连接词(引导词) + 宾语从句连接词:从属连词that, whether, if 连接代词 Who, whom, whose, which, what 连接副词 where, how, why, when一. 连词 (引导词)1. 当宾语从句是陈述句时(包括肯定句和否定句), 连词由that引导, 因为that在从句中不作任何成分, 也没有任何具体意思, 因此在口语或非正式文体中常省略。 Jane said (that) she wasnt late for the meeting.2. 当宾语从句是特殊疑问句时, 由特殊疑问词充当连接词, 因为该特殊疑问词(即连接词)在从句中担任一定的句子成分, 具有一定的意义, 所以不可以省略。Do you know what he said just now?I dont remember when we arrived3. 当宾语从句是一般疑问句时,由连词whether或if引导(口语中常用if),因为if/whether翻译成是否,具有一定的意义,所以不能省略。 Lily wanted to know if /whether her grandma liked the handbag . Lets see if /whether we can find out some information about that city 注意: 关联词只能用whether不能用if 表示 “是否”的情况如下： A) 在表语从句和同位语从句中。如： The question is whether the film is worth seeing. The news whether our team has won the match is unknown.B) 在主语从句中，只有用it 作形式主语时, whether和if 都能引导主语从句, 否则, 也只能用whether。如: Whether we shall attend the meeting hasnt been decided yet. It hasnt been decided whether (if) we shall attend the meeting.C) 在介词之后。(介词往往可以省略) 如: It all depends (on) whether they will support us.D) 后面直接跟动词不定式时。如： He doesnt know whether to stay or not.E) 后面紧接or not 时。如： We didnt know whether or not she was ready. 关联词if, whether均可使用的情况如下： A) 引导宾语从句。如： I wonder if (whether) the news is true or not. B) 在 “be+形容词” 之后。如： He was not sure whether (if) it is right or wrong.宾语从句要注意的几个问题 1. 时态呼应 2. 否定转移: 3. 形式宾语it的使用 注:在think, believe, suppose, expect 等动词之后,宾语从句中谓语的否定常转移到主句的谓语上。 I dont think he will see you. I dont believe he will go. 注:在接复合宾语的句子中(S+Vt+O+Oc), 为了保持句子平衡, 用it 作形式宾语,将从句放于句尾, 常接复合宾语的动词有: make, find, see, hear, feel, think. I think it necessary that we take plenty of hot water every day. Ithinkitapitytowastethefood表语从句的用法在复合句中用作表语的从句是表语从句, 引导表语从句的关联词与引导主语从句的关联词大致一样,表语从句位于连系动词后,有时用as if引导。其基本结构为:主语 + 系动词 + that从句。 Thats what we should do. Thats why I want to see you. 1. be, seem, look等动词后均可跟表语从句： My suggestion is that we should go shopping. It seems that it is going to rain. 2. as if, because 也可引导表语从句。 It looks as if its going to rain. It was because I got up late. 3. 在非正式文体中,引导表语从句的that可以省略。如: The trouble is (that) he is ill.注意:在表语从句中,当reason做主语时,引导词只能用that,不能用because,如:他迟到的原因是因为他没有赶上早班车。 The reason why he was late was that he didnt catch the early bus. 同位语从句同位语从句一般跟在名词fact, news, promise, truth, belief, thought, idea, answer, information, knowledge, doubt, hope, law, opinion, plan, suggestion后面, 用以说明或解释前面的名词.The news that our team has won the match is true.His delay is due to the fact that the car went wrong halfway.注: 1. that 引导同位语从句that 引导定语从句的区别: 引导同位语从句的that 无实际意义, 不作从句的任何成分, 而引导定语从句that从句的某个成分He told me the news that our team won the match.He told me the news that was very exciting.We are interested in the news that some foreig