一．名词性从句的概念：指具有名词性质的从句，包括主语从句，宾语从句，表语从句和同位语从句。 二．名词性从句的引导词： 连接词 连接代词 连接副词 三．引导词的作用： ①连接词只有连接的功能，不在从句中充当句子成分。 ②连接代词和连接副词除了起到连接作用外。还要在从句中担任主语，宾语，表语，定语，或状语等成分。 注：名词性从句的语序：陈述语序★ 四．
名词性从句的用法： （一）主语从句： 1．主语从句的引导词：that, whether, 连接代词，连接副词。 ---That he is still alive is a wonder. ---When we will hold the meeting is a problem. ---Whatever he did was right. 2． 主语从句需注意的问题： 有时主语从句放在句首显得很笨重,常用 it 作形式主语而把主语从句移到句末。 ①常用 it 作形式主语的句型有： a. It+be+形容词+that/wh-从句 （常见形容词有：certain/clear/obvious/important/likely/possible/probable/true/necessary/amazing/surprising…） ---It is certain that she will do well in the exam. ---It is very difficult what you are doing. b. It+be+名词+that/wh-从句 （常见名词有：no wonder, no surprise, a pity, a surprise, a question, a shame, an honor, a good thing, a fact… ） ---It’s a pity that we can’t go. ---It remains a question whether it is true. c. It+be+过去分词+that/wh-从句 （常见过去分词有：said/believed/reported/suggested/accepted/announced/decided/expected/known/proved…） ---It is said that Mr. Green has arrived in Beijing. ---It has been suggested that much should be done to prevent the river from being polluted. d. It+不及物动词+that/wh-从句 （常见不及物动词有：appear/seem/happen/matter/occur to sb.） ---It doesn’t matter whether she will come or not. ---It happened that I was out that day. ②如果主句是疑问句，则必须用 it 作形式主语，主语从句置后： ---Is it true that he is the girl’s father? ③what 引导的主语从句一般不用 it 作形式主语，直接将主语从句置于句首： ---What we need is money. （二）宾语从句： 1．宾语从句的引导词：that, whether, if, 连接代词，连接副词。 ---I don’t know if you can help me. ---I’ll tell you why I asked you to come. 2．宾语从句需注意的问题： ①介词后接宾语从句：
that, if, whether, as if, as though, because who, whoever, whom, whomever, what, whatever, which, whichever, whose when, where, why, how, how 构成的短语
---Success depends on whether we make enough effort. ---She laughed at what we said. a. that 通常不作介词宾语，但可在介词 in, except, besides, but 后引导宾语从句： （现多被看做是固定短语：in that:因为； except/besides that:除了； but that:要不是） ---He would have helped us but that he was short of money at that time. ---I know nothing about him except that he is a graduate of Beijing University. b. whether 和 if 引导宾语从句时一般可以互换，但介词后只能用 whether，不用 if： ---It is a question of whether we should go. ②形容词后接宾语从句： （某些表示感情色彩的形容词作表语时后面可跟一个意义上相当于宾语的名词从 句） （常见形容词有：afraid, aware, certain, sure, glad, pleased, surprised, doubtful, confident 等） ---I’m not sure what I ought to do. ---I’m surprised that I didn’t see all that before. ③如果宾语从句后跟有补语，常用 it 作形式宾语，将从句放到补语之后： ---I think it important that young people master two languages. ---He has made it clear that he will not give in. ④宾语从句中 that 的省略：一般情况下，引导宾语从句的 that 可省略，但如果有两个 that 引导宾语从句， 第二个 that 通常不能省略，以免引起歧义： ---I know (that) you have studied English, and that you have written an English poem. ⑤宾语从句的否定转移： 当主句谓语动词为 think, believe, suppose, expect, guess 等表示“认为，猜想，估计”的意思时，其后的宾语 从句如果带否定意义，通常将否定词 not 前置于主句谓语上： ---I don’t think you are right. ---I don’t believe they have finished their work yet. 注：如果主语为第一人称，反义疑问句看从句谓语，如果主语为二三人称，反义疑问句看主句谓语： ⑥宾语从句的时态变化规律： 当主句是一般现在时，从句可根据需要用任何时态。 当主句是一般过去时，从句只能使用过去范围内的任何时态。 （客观真理除外） ---She said that she would come. ---The teacher told us that the sun rises in the east. （三）表语从句： 1．表语从句的引导词：that, whether, as if, as though, because, 连接代词，连接副词。 ---The question is whether he is honest. ---It looked as if it was going to rain. 2．表语从句需注意的问题： ①as if, as though 引导表语从句时根据实际情况既可用一般语气也可用虚拟语气。 ---It looks as if we will be late. ---The patient looked as if he had been ill for a long time. ②固定句型：The reason why….is/was that…(不能用 because) ---The reason why he didn’t attend the meeting was that he was seriously ill. ③because 可引导表语从句，但与之同义的 since, as, for 等不能引导表语从句： ------It is because I love you too much. （四）同位语从句： 1．同位语从句的引导词：that, whether, 连接代词，连接副词。 ---We heard the news that our team had won. ---I have no idea when he will come back.
2．同位语从句需注意的问题： ①同位语从句的先行词多为词义比较抽象的名词，往往要求用从句来具体说明这一名词的实际内容或对该 名词作进一步解释。 （常见名词有： fact, news, idea, thought, question, report, possibility, belief, doubt, evidence, hope 等） ---The fact that the seawater cannot be used for drinking is known to all. ---An idea occurred to him that he might go there by air. ②同位语从句与定语从句的区别： 同位语从句：that 不充当句子成分；从句与先行词之间是同位关系；从句说明先行词的具体内容；先行 词有范围限制 定语从句：that 充当句子成分；从句与先行词是修饰与被修饰关系；从句说明先行词的性质特征；先行 词无范围限制 ---The news that he won the first prize is true. （同位语从句） ---The news that you told me yesterday is true. （定语从句） 五．what 的特殊用法： what 引导名词性从句时可表示几个特殊概念： ---He is no longer what he was. (what 表示“…的人或样子”) ---Our income is now double what it was ten years ago. (what 表示“…的数目或数量”) ---He was born in what is now known as Shanghai. (what 表示“…的地方”) 六：含有感叹句的名词性从句： ---You can’t imagine what difficulty I had finding this shop. ---You never thought what a wonderful time we had at the party. 七．含有插入语的名词性从句： ---Many people thought little of me, but I did what I thought was right. 八．几组引导词的用法区别： 1．what 与 that: what: 在句中可作主语，宾语，表语，意为“什么” that: 仅起连接作用，本身没有实际意义，在从句中不充当任何句子成分（引导宾语从句常可省略） ---He doesn’t know what she likes. ---I believe (that) he will come to see us. 2. whether 与 if: ①两者均可引导宾语从句，表示“是否”，常可互换： ---He didn’t tell me if/whether he would come. a. 引导宾语从句但置于句首或介词后时只能用 whether： ---Whether he has left, I can’t say. ---I worry about whether I hurt her feelings. b. 直接与 or not 连用时只能用 whether（若不直接与 or not 连用，也可用 if） ---I will write to you whether or not I can come. (让步状语从句) ---I don’t know whether/if he will win or not. c. 与不定式连用时只能用 whether: ---I’m not sure whether to stay or leave. ②引导主语从句，表语从句和同位语从句时只能用 whether: ---Whether he will come is still a question. ---The question is whether he will come. ---The question whether we need it has not been considered.
★总结：若 whether 和 if 同时出现，意为“是否”时，首选 whether。 3．that 与 whether(if): that 表示肯定，明确的概念，而 whether(if) 则表示不肯定，不明确的概念。 ---I doubt _________ he will come. ---I don’t doubt ________ he will succeed. ---Do you doubt ________ he will win? 4．who 与 whoever: who 引导名词性从句强调一件事情，而 whoever 引导名词性从句强调人，相当于“anyone who” ---I will give the tickets to ___________ wants it. ---_______ spoke at the meeting is unknown.