关于名词性从句

Question

请你介绍下名词性从句

Answer 1

一、什么是名词性从句？
　　在主从复合句中有名词特征的从句叫名词性从句，按句法功能分为主语从句、宾语从句、表语从句和同位语从句，可由that, whether, if, who, what, which, when, where, why 等词来引导。
　　名词性从句可做主语、宾语和表语。名词性从句都用陈述句语序。　　Eg.
　　----Why he left remained a secret.
　　----That he is lying is quite clear.
　　----Whether he will stay to help us out is not known yet.
　　----My hometown is no longer what it used to be.
　　-----That all depends on whether it will rain tomorrow evening.
　　-----The fact that he was fired surprised everyone in the company.　　二、连接词的使用
　　1. whether与if
　　表“是否”时宾语从句可用if和whether，其它名词性从句只用whether。
　　另外在以下情况多用 whether
　　●　 whether…or not…
　　●　 whether to do
　　●　 在介词后， 如：Everything　 depends on whether we have enough time.　　2. that在引导主语从句、同位语从句、表语从句时不省略，引导宾语从句时可省略。
　　Eg.
　　----That he has disappeared worries his parents.（主语从句）
　　---He left me a message that he would buy me a ticket to the rock concert.（同位语从句）　　3．what与 that
　　在句中担任成分的用what，不担任成分的用that.
　　Eg.
　　----That he will come is certain.
　　---What they advised me to do was quite helpful.
　　----The problem is what we should do next.
　　----The problem is that we should do it next.　　4. 由that引导的主语从句通常用形式主语来代替.
　　Eg.
　　---It worries his parents that he has disappeared.
　　----It is not likely that he can win the game.
　　----It is a big surprise that he is still alive.　　5.由that引起的宾语从句,在believe, think, suppose后常省略
　　在think, believe, suppose, expect等动词引起的宾语从句中,从句的谓语是否定时,要将否定词放在前面。
　　Eg.
　　----I don’t think you can beat me.
　　---I don’t think you are right.　　因此，当主语为第一人称，以这些动词引起的句子的反意疑问句应以从句的形式为主。
　　Eg.　 ---I think you are right, aren’t you ?　　但注意：
　　eg.　 ---I don’t think you are right, are you?(此句实际否定的是从句， 所以反意部分用肯定形式)　　三、同位语从句
　　同位语从句一般放在fact, hope, idea, order, suggestion, promise, truth, view等名词后，进一步说明名词所表示的具体内容，可由that, whether, how, when, where, why等词引导。
　　Eg.
　　----Everybody is clear about the fact that he has never worked hard enough.
　　----I totally agree to your suggestion that we have a rest.
　　----Word came that our team had won the game.　　四、同位语从句和定语从句的区别
　　同位语从句是名词性从句，定语从句是形容词性的从句。that在从句中做成分则为定语从句；that在从句中不做成分则为同位语从句。
　　Eg.
　　----The news that he told us is not true.（定语从句）
　　---The news that our team won the game made us happy.（同位语从句）
　　----He put forward the suggestion that the second question should be discussed first. （同位语从句）
　　---The suggestion that he had put forward was turned down. （定语从句）　　注意：在具体应用中如遇到选项有that和which时， 不要轻易做决定， 应先确定是什么从句，