名词性从句的重点、难点、考点：名词性从句在功能上相当于名词名词性从句的定义:在复合句中起名词作用的从句叫名词性从句(Noun Clauses）。
名词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）引导名词性从句的连接词1、连接代词：who, whose, whom, what, which。
有词义，在从句中担任成分，如主语、表语、宾语、或定语等。
2、连接副词：when, where, why, how。
有词义，在从句中担任成分，作状语。
3、连接词：that, whether, if, as if。
that无词义，在从句中不担任成分，有时可省略；as if（好象）虽有词义，但在从句中不担任成分。
注意：连词的选用：依据“缺什么补什么”原则确定正确的连词。
如果句子中缺主语，指人用who，指物用what；如缺宾语，指人用whom，指物用what；如缺时间状语用when；地点状语用where；原因状语用why；方式状语用how；定语用what或which；什么都不缺用that。
whether 和if（是否），1. It’s not immediately clear ____ the financial crisis will soon be over .A. sinceB. whatC. whenD. whether2. As a new diplomat , he often thinks of _____ he can react more appropriately on such occasions.A. whatB. whichC. thatD. how3. When asked ____ they need most , the kids said they wanted to feel important and loved. \A. whatB. whyC. whomD. which4. The last time we had great fun was ___ we were visiting the Water Park .A. whereB. howC. whenD. why5. Why not try your luck downtown, Bob? That’s _____the best jobs are .A. whereB. whatC. whenD. why6._______ you don't like him is none of my business. (上海1992)A. WhatB. WhoC. ThatD. Whether7.Go and get your coat．It's ____ you left it．A. whereB. thereC. here whereD. where there（二）that在名词性从句中的用法that 引导名词性从句不充当任何成分，没有具体意义。
以下情况that不能省略：1.主、表、同从句不能省That I can pay back the help people give me makes me happy.It is certain that he will succeed.The order that all the soldiers should stay still is given by the general.The fact is that he has not been seen recently.2.宾语从句中的that 一般可以省，但以下情况不能：a. 并列宾语从句中第一个that 可以省，后面的都不能省。
I knows (that) he is a worker and that he lives in Shanghai.b.介词in , except 后面的that 不能省。
The reason lies in ______she works harder than others do.The higher income tax is harmful in ______it may discourage people from trying to earn more.c.主句动词后有其它从句插入，或连接词后有其它从句插入，that 不能省。
He judged ______ because he was a child , he didn't understand what he said .Everyone knows ____ happened and_____ she was worried .A that, that B. what, that C. what, / D. that , whatd. it 做形式，that做真正的宾语引导从句，that不能省。
I think it difficult ____we finish the task in only one day. A / B. that C. what D. whiche.若主句的谓语动词是appear，agree，learn，suggest，observe等时，that通常不可省略。
例如：We agreedthat all the students must plant trees in the park.1. China’s success in manned-spacecraft travel shows ____ our country has become one of the greatestpowers in space research. A. what B. which C. 不填 D. it that（三）、whether与if的辨用whether与if都可以引导宾语从句，常可互换。
但在下列情况下用whether。
a. 主语从句b. 表语从句c. 同位语从句 e. 介词后的宾语从句f.后接动词不定式(whether to do sth.)g .whether or not 连在一起引导宾语从句时不用if___ the meeting will be held in Beijing is not known yet.A. WheneverB. IfC. WhetherD. That2.At first he hated the new job but decided to give himself a few months to see ____ it got any better.A. whenB. howC. whyD. if3._____we’ll go camping tomorrow depends on the weather.A. IfB. WhetherC. ThatD. Where4. What the doctors really doubt is _____my mother will recover from the serious disease soon. (上海2001)A. whenB. howC. whetherD. why（四）名词性从句中一律使用陈序语气。
e.g. He asked how much I paid for the violin.I want to know what he has told you. 我想知道他告诉了你什么。
She always thinks of how she can work well. 她总是在想怎样能把工作做好。
1.No one can be sure ____ in a million years.A. what man will look likeB. what will man look likeC. man will look like whatD. what look will man like2.You can’t imagine ____ when they received these nice Christmas presents.A. how they were excitedB. how excited they wereC. how excited were theyD. they were how excited3. The photographs will show you ____．（MET1989）A. what does our village look likeB. what our village looks likeC. how does our village look likeD. how our village looks like4. Someone is ringing the doorbell. Go and see ___________. (NMET2000)A. who is heB. who he isC. who is itD. who it is5. Can you make sure ______ the gold ring? (NMET1990)A. where Alice had putB. where did Alice putC. where Alice has putD. where has Alice put6. He asked ________ for the violin. (NMET1991)A. did I pay how muchB. I paid how muchC. how much did I payD. how much I paid（五）名词性从句中虚拟语气的使用情况1、在表示“命令、建议、坚持、要求”的名词性从句中，要用“should+动词原形”形式，should可以省略。
e.g. I made a suggestion that he (should) go there at once.I suggested that he (should) go there at once.The suggestion was that he (should) go there at once.I insist that she (should) do her work alone. 我坚持要她自己工作。
The commander ordered that troops (should) set off at once. 司令员命令部队马上出发\ He insisted that he _____ the money and ____ he ____ set free.A. didn’t steal , / wasB. steal , that , shoud beC. didn’t steal , that , should beD. steal , / was2、wish引导的宾语从句中要用虚拟语气，分与现在、过去、将来相反三种情况。