专题十 名词性从句
考点一 各种名词性从句的定义
名词性从句包括主语从句、宾语从句、表语从句和同位语从句。名词性从句是一种具有名词功能的非独立分句。名词性从句主要有四种从句结构：以that引导的从句；以whether/if引导的从句；以特殊疑问词who，where，why等引导的从句；以what或whever等引导的从句。此外，as if/as though也可引导表语从句。
[活学巧练] 完成句子
①It is quite clear ________ the whole project is doomed to failure.
很明显，整个项目注定失败。
②They couldn't understand ________ I refused it.
他们不明白我为什么拒绝它。
③I have no idea __________ the meeting will be held.
我不知道会议是否会举行。
④He has made the company ________ it is today.
他把公司办成了今天这个样子。
答案：①that ②why ③whether ④what
考点二 that 引导的名词性从句
that引导名词性从句时，它本身没有意义，在从句中不担任任何句子成分，但引导主语从句、表语从句、同位语从句时不能省略，在宾语从句中有时可省略。
一、 that 引导主语从句
1. that引导主语从句位于句首时，本身无意义，但是不可省略。
2. that从句作主语时，常用it作形式主语，常见的句型有：
(1)It＋be动词＋形容词(obvious，true，natural，surprising，good，wonderful，funny，possible，likely，certain，probable，etc. )＋that从句；
(2)It＋be动词＋名词词组(no wonder，an honour，a good thing，a pity，no surprise，etc. )＋that从句；
(3)It＋be动词＋过去分词(said，reported，thought，expected，decided，announced，arranged，etc. )＋that从句。
[活学巧练] 单句语法填空
①________ you didn't know the rules won't be an excuse for your failure.
②It is obvious to the students ________ they should get well prepared for their future.
答案：①That ②that
二、 that 引导宾语从句
1. 常见的可以接that(that可以省略)从句作宾语的动词有see，say，know，imagine，discover，believe，tell，show，think，consider等。在可以接复合宾语的动词之后，如think，make，consider等，可以用it作形式宾语。
2. that从句一般不能充当介词宾语，偶尔可作except，in的宾语。
[活学巧练] 单句语法填空
①I truly believe ________ beauty comes from within.
②Tom is a nice boy，except ________ he is sometimes late for school.
③I find ________ necessary ________ we should spend more time practising spoken English.
答案：①that ②that ③it；that
三、 that 引导表语从句和同位语从句
1. that引导表语从句时，一般不能省略。
The fact is that we have lost the game.
事实是我们已经输了这场比赛。
2. that引导同位语从句时，应在某些抽象名词如fact，hope，desire，thought，suggestion，idea，news，problem，possibility等后，对前面的名词起补充说明的作用，that只起引导作用，在从句中不充当成分，但一般不能省略。
The news that our football team won the match was encouraging.
我们足球队赢了比赛的消息令人鼓舞。
[活学巧练] 单句语法填空
①My decision is ________ all of us are to start at 6 o'clock tomorrow morning.
②The manager put forward a suggestion ________ we should have an assistant. There is too much work to do.
答案：①that ②that
考点三 whether/if (是否)引导的名词性从句
1. whether和if在宾语从句中经常可以互换，但下列情况常用whether，不用if：
(1)与or或or not连用时，只能用whether；
(2)从句作介词宾语时，只能用whether。
2. 在引导主语从句、表语从句和同位语从句时，一般用whether不用if。
[活学巧练] 单句语法填空
①It remains to be seen ___________ the newly formed committee's policy can be put into practice.
②The question is ___________ it is worth trying.
③He asked her the question ___________ they can be friends.
④I worry about ___________ he can pass through the crisis of his illness.
答案：①whether ②whether ③whether ④whether
考点四 who ， why ， how ， where ， when 等引导的名词性
从句 1. who，why，how，where，when等引导主语从句时，常用it作形式主语。
2. 能接以上词引导的宾语从句的动词很多，常见的有see，tell，ask，answer，know，decide，imagine，suggest，doubt，wonder，show，discuss，understand，inform，advise等。
3. 以上词可引导介词的宾语从句。
4. 以上词还可引导表语从句和同位语从句。
[活学巧练] 单句语法填空
①________ we understand things has a lot to do with what we feel.
②________ Li Bai，a great Chinese poet，was born is known to the public，but some won't accept it.
③I don't know ________ it was that our headmaster was absent from such an important meeting.
④Some students even have no idea of ________ they are studying，so they waste much time playing.
答案：①How ②Where ③why ④why
考点五 what ， whever 引导的名词性从句
1. what引导名词性从句时，意为“什么”或“……的”，在从句中用来作主语、宾语、表语或定语。
2. whever引导名词性从句时，意为“任何……”或“无论……”，含有强调的语气。
[活学巧练] 单句语法填空
①Your support is important to our work. ___________ you can do helps.
②___________wants to stay in a hotel has to pay their own way.
③We promise ___________ attends the party a chance to have a photo taken with the movie star.
④A ship in harbor is safe，but that's not ________ ships are built for.
答案：①Whatever ②Whoever ③whoever ④what
语法填空题主要考查名词性从句中的连接词。名词性从句包括主语从句、宾语从句、表语从句、同位语从句，其连接词一般不可省略(宾语从句中的that可省略)。
[典题试做]
在空格处填入适当的连接词
1. [2020·浙江卷]Over thousands of years, they began to depend less on ________ could be hunted or gathered from the wild, and more on animals they had raised and crops they had sown.
2. [2019·江苏卷]Scientists have obtained more evidence ________ plastic is finding its way into the human body.
3. [2018·全国卷Ⅲ]I'm not sure ________ is more frightened，me or the female gorilla(大猩猩) that suddenly appears out of nowhere.
4. [2018·北京卷]Without his support，we wouldn't be ________ we are now.
5. [2018·北京卷]This is ________ my father has taught me—to always face difficulties and hope for the best.
6. [2018·江苏卷]By boat is the only way to get here，which is ________ we arrived.
答案：1. what 2. that 3. who 4. where 5. what 6. how
[高效演练]
Ⅰ. 单句语法填空
1. [2021·江苏省南京市高三第三次模拟]—The designers are over the moon. What's up?
—They've reached an agreement on ________ the bonuses are to be divided later.
2. [2021·江苏省连云港市赣榆区高三高考仿真训练]The setting of the film Zootopia may be limited in the city full of kinds of animals, but ________ it exposes about human nature is quite broad.
3. [2021·江苏省南通等苏北七市高三三模]In the years to come, everyone will be able to take pride in ________ we responded to this challenge.
4. [2021·天津市河北区高三一模]—What do you think made the 92nd Academy Awards so special?
—________ Parasite from South Korea won a total of four Oscars.
5. [2021·吉林一次调研]The ideal nap depends on ________ you want from that nap.
6. [2021·河北衡水中学一调]There is no doubt ________ the event will attract more visitors to enjoy visiting this wonderful city.
7. [2021·湖北重点高中联考]Experts hold the opinion ________ a small amount of stress can be good in exams.
8. [2021·安徽江淮十校二次联考]It is believed that advertising can often be an indicator for ________ society considers to be socially acceptable and desirable at the time.
答案：1. how 2. what 3. how 4. That 5. what 6. that
7. that 8. what
Ⅱ. 语法填空(名词性从句专练)
1. ________ worries my classmate Mary a lot these days is 2. ________ she puts on too much weight and she is frequently ill. She has some doubts 3. ________ she eats too much fast food high in fat or sugar. Also，with the College Entrance Examination approaching，she becomes more stressful and she can't sleep well these days. Maybe this is 4. ________ she becomes fatter these days，she thinks. 5. ________ she becomes slimmer and healthier has been her main task. So she wants to consult some experts and gain some instructions. But where she could get better suggestions and 6. ________ will give her better advice also puzzle her. It is her parents' suggestion 7. ________ she should consult Professor Wang in Zhongshan Hospital. Professor Wang suggests 8. ________ shekeep a balanced diet first. She should eat vegetables and fruit high in fiber，vitamin and protein. What's more，if she wants to lose weight，she had better take regular exercise more than half an hour a day. Mary asked Professor Wang 9. ________ she should take exercise. Professor Wang advised her to take exercise at 5 o'clock in the afternoon. That is 10. ________ she will have more time to do sports. It is with the help of Professor Wang that Mary has become much healthier now.
答案：1. What 2. that 3. whether 4. why 5. How
6. who 7. that 8. that 9. when 10. because