名词性从句的连接词选用

1、名词性从句的连接词选用名词性从句包括主语从句，表语从句，宾语从句和同位语从句引导同位语从句的词通有连词that，whether，连接副词how,when,where等。（注：if不能引导同位语从句。）。在各种考试中，其最主要的考查内容为连接词的选用。名词性从句的连接词可细分为以下四种：（1）以that来引导从句；（2）以whether/if引导从句；（3）以特殊疑问词引导从句；（4） 以关系代词/副词引导从句。一、以that引导从句当从句的意思已完整时，名词性从句用that引导，that在从句中不作任何句子成分，仅起连接作用。如：It is certa in that he will do w

2、ell in his new job.（主语从句）Do you know that he has bee n admitted to Beiji ng Uni versity?（宾语从句）My decisi on is that we are to start at 6 tomorrow morning.（表语从句）The n ews that our team had won the game excited everybody. （同位语从句）当用that引导从句时，需注意以下情况：1 在主语从句中，that 一般不可省略，尤其是当主语从句位于句首时，它绝对不可省略。 如：That our

3、 team had won the game was good n ews to us.2. 在宾语从句中，that可省略。但当句中有两个并列的宾语从句时，引导第二个宾语从句 的that不可省略。如：Everybody knows （that） the earth goes round the sun.Everyone knew what happe ned and that she was worried.3. 当句子是以it作形式宾语时，引导宾语从句的that不可省略。如：He has made it clear that he will not give in.4. that 一般不能引

4、导介词的宾语从句，偶尔可在except, but, besides和in （在于；在方 面）的后面引导宾语从句，that不可省略。如：Your homework is quite good except that you have made two small mistakes.The reas on lies in that she works harder tha n the others do.He differed from other people in that he always looked farther ahead in his work.在其它介词后面需要用that引导宾

5、语从句时，必须用 it作形式宾语。如：You may depe nd on it that I shall always help you.5 .在表语从句和同位语从句中，that不可省略。如：My advice is that you must give up smok ing right now.The fact that he is a thief shocked all of us.二、以 whether/if引导从句引导名词性从句的 whether/if意为"是否”。在使用时，要注意两者存在以下区别。1. 在主语从句中，whether既可引导位于句首的主语从句，也可引导用i

6、t作形式主语的主语 从句，而if只能引导以it作形式主语的主语从句。如：Whether the work can be completed on time is doubtful.It is doubtful whether/if the work can be completed on time.2. 在宾语从句中，当其后紧跟or not时，只能用whether，不能用if。如：I don ' t care whether/if he comes or not.I don ' t care whether or not he comes.3. 在介词后面的宾语从句中，只能用w

7、hether，不能用if。如：It all depe nds on whether they will come back.4. 在表语从句和同位语从句中，只能用 whether，不能用if。如：The problem is whether the money will be eno ugh.I have no idea whether the money will be eno ugh.三、以特殊疑问词引导从句英语中所有用来构成特殊疑问句的特殊疑问词均可以用来引导名词性从句，其选择取决于从句句意的需要。如：It remained unknown who （谁） let out the n e

8、ws.I don ' t know what （什么）I was thinking of.The problem is where （哪里）we should stay.My question how （怎样）I shall get in touch with him has not been answered.选择特殊疑问词需注意的情况：1. 要注意特殊疑问词在从句中所担当的句子成分：疑问代词可作主语、宾语和表语，而疑问副词（where, when, why, how ）只能作状语。如:I can' t imagine who did it.（作主语）I can' t

9、 imagine how he did it. （作状语）2. Who在从句中既能作主语，也能作宾语，而whom只能作宾语。如：It has n ' t bee n decided who will man age the compa ny.They haven ' t decided whom they should help.四、以关系词引导从句用关系词引导的名词性从句又可称作名词性关系从句，因为它实际上是先行词与在其后的定语从句的结合。引导这种名词性从句的关系词有：what（=the thi ng that）, whoever（=a nyone who）,whicheve

10、r（=anyone/anything that）, where（=the place where）, when（=the time when） 等。如： What they n eed is a good rest.I can judge by what I know of him.Whoever did this job must be rewarded.Whichever he likes will be give n to him.We shall not forget whe n the meet ing will be held.She walked up to where he s

11、tood.用关系词引导名词性从句时需要注意wh-ever与no matter wh-的区别。Wh-ever既可引导名词性从句，又可引导让步状语从句；而no matter wh-只能引导让步状语从句。如：Whatever I said, he wouldn ' t listen to me. （=No matter what I said, he wouldn' t listen to me.）（引导让步状语从句）He would believe whatever I said.（引导宾语从句）Whichever/No matter which you choose, the others will be offen ded.Take whichever you like.这里句中的 whichever在不能用 no matter what替换最后，关于名词性从句的连接词要指出的是，根据句意，引导表语从句的还可以是as if/asthough, because, as 如：It looks/s