2018高考在即（考生必知的英语试卷名词性从句知识技巧）
首先我们来整理一下到底什么是名词性从句？
在句子中起名词作用的句子叫名词性从句。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，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
一、名词性从句的分类
1、主语从句
That she was chosen made us very happy.
What caused the accident is a complete mystery.
要明白“that”在主语从句中不作任何成分，但放在句首时不能省略。
但是如何怎么才能 that 不放在句首呢?
为了句子结构平衡，避免“头重脚轻”，常用it作形式主语，而把从句放在后面。
形式主语常用结构：
It+ be +名词+ that从句
It is a pity that we won"t be able to go to the south to spend our summer vacation.
It+ be +形容词+ that从句
It is very likely that they will hold a meeting.
It+动词的过去分词+ that从句
It is known to all that the gun powder was first invented by the Chinese.
2、宾语从句
宾语从句在复合句中作主句的宾语，宾语从句一般放在动词、介词后。
She explained that she was late because of the heavy traffic.
有时要用it作形式宾语，而把宾语从句放在句子的后面。
He has made it clear that he will not give in.
宾语从句注意事项
使用虚拟语气的场合
(1)在表示要求、命令、建议、决定、坚持等意义的动词后，宾语从句常用“(should)+ 动词原形”。
I insist that she (should) do her work alone.
Suggest
（1）暗示、表明、觉得(不虚拟)
E.g.：1. Her pale face suggested that she was(be)ill and I suggested she should go(go)to the hospital at once.
（2）坚持要求(虚拟)
Insist
（1）坚持认为(不虚拟)
E.g.：The manager insists that he is (be)right and he insists that everyone should have(have)a new plan for the program.
(2)表示愿望的wish后的宾语从句中须用虚拟语气。
I wish I could fly. I wish I had known it before.
宾语从句谓语动词时态的选择
(1) 当主句为现在时或将来时,宾语从句为任意时态.
(2) 若从句是一个客观真理、科学原理、自然现象，从句用一般现在时。
The teacher said that the moon goes around the earth yesterday.
(3)当主句是过去时(could, would除外)，从句则要用相应的过去时态①从句用一般过去时或过去进行时，表示与主句谓语动词动作同时发生
I only knew he was studying in a western country,but I didn’t know what country he was in.
He asked me if I was reading the story The Old Man and the Sea when he was in.
②从句过去完成时，表示该动作发生在主句谓语动作之前
He told me that he had told Mary about the meeting already.
③从句谓语用过去将来时，表示该动作发生在主句谓语动作之后
The reporter asked if the government would take necessary measures to put down the to-do.
3、表语从句
在句中作表语的从句叫表语从句。表语从句位于连系动词后，其基本结构为：主语 + 系动词 + 从句。
The problem is how we can get the things we need.
The scissors are not what I need.
注意：
(1)whether可以引导表语从句，但是if不可以。
(2)此外，as if/as though，because，why也可以引导表语从句。As if/as though引导表语从句时，根据从句的内容，有时需要使用虚拟语气。
It looked as if it was going to rain.
He looks as if he were an artist.
That’s because he didn’t work hard enough.
That was why I asked for three days’ leave.
需要注意的，当主语是reason时，表语从句要用that引导而不是because。
The reason why he was late was that he missed the train by one minute this morning.
4、同位语从句
同位语从句说明其前面的名词的具体内容。同位语从句通常由that引导，可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。
The news that we won the game is exciting.
I have no idea when he will come back home.
特殊疑问词也可以引导同位语从句，注意陈述语序。
My question how I shall get in touch with him has not been answered.
二、名词性从句的连接词分类
1.that（无含义，不充当成分）
2.whether,if（有“是否”的含义，但不充当成分）
3.连接代词：what, whatever, who, whoever, whom, whomever, whose, which, whichever.（在从句中做主语、宾语、表语和定语）连接副词：when, whenever, where, wherever, how, however, why （在从句中做状语）
4. as if，as though，because（不充当成分，在名词性从句中只引导表语从句）
三、名词性从句的考查形式
1.考查名词性从句的引导词，通常都是在无提示型的试题中，即试题只给出空格而不给提示词，让考生填入恰当的引导词。
例1·语法填空：I didn’t understand why this would happen and my credit card had already been charged for the reservation. 此题考查why引导的宾语从句。
例2·完形填空：But every day， we would sit by the lake， looking at the house and dreaming of what it would be like to live there. 此题考查what引导的宾语从句。
例3·短文改错：After looking at the toy for some time， he turned around and found where his parents were missing. 此句中，正确答案为：去掉where，或把where改为that。（that） his parents were missing是一个宾语从句。
2.考查名词性从句的时态、语态，通常出现在语法填空和短文改错这两大题型中。
例4·短文改错：Do you want to know why we move last week？ 此句中，正确答案为：把move改为moved。why we moved last week是一个宾语从句，当名词性从句的主句是一般现在时时，从句本身的时态不变。
例5·语法填空：He sold or exchanged some of the milk in the towns nearby for other food and made cheese and butter for the family with what was left （leave）. 此句中，what was left是一个宾语从句，作介词with的宾语。因为主句是一般过去时，所以宾语从句也要用一般过去时。
四、名词性从句解题步骤
1.划分句子成分，找出名词性从句。
例6·语法填空：As natural （nature） architects， the Pueblo Indians figured out exactly thick the adobe walls needed to be to make the cycle work on most days.此句的主语是the Pueblo Indians，谓语动词是figured out， thick the adobe walls needed to be to make the cycle work on most days是一个宾语从句。
2.根据句意，将STEP 1中划分出的名词性从句的意思翻译出来，并将其还原成一个原始的句子。该原始的句子可以是陈述句、一般疑问句、特殊疑问句。
以例6为例。根据句意，此例中划分出的名词性从句的意思应该为：这些土坯墙需要很厚，才能保证这个热循环持久有效。把该名词性从句还原成一个原始的句子，“这些土坯墙需要有多厚”应该是一个特殊疑问句，即“How thick did the adobe walls need to be？”
3.根据名词性从句的规则（考虑引导词、时态、陈述句语序），写出一个正确的名词性从句。
仍然以例6为例。在STEP 2中，考生根据句子结构和句子意思，还原出了一个原始的句子——How thick did the adobe walls need to be，现在考生要根据名词性从句的基本规则（考虑引导词、时态、陈述句语序），写出一个正确的名词性从句：How thick the adobe walls needed to be。所以，例6空格的正确答案为“how”。