英语名词性从句重难点精讲.docVIP

英语名词性从句重难点精讲 名词性从句重难点精讲 　　名词性从句就是在句子中起名词作用的从句。根据这种从句在句子中所充当的语法成分,又可分为主语从句,宾语从句,表语从句和同位语从句。我们学过的状语从句(又叫副词性从句)和定语从句(又叫形容词性从句)也是根据这些从句的句法功能而命名的。例如: What he said is not true.（主语从句） I don’t trust what he said.（宾语从句） Such is what he said.（表语从句） The news that he was praised is not true.（同位语从句） It was raining when we got there.（状语从句） The news that he gave us is not true.（定语从句） 1.名词性从句的引导词 总的来说,名词性从句的引导词可分为三类(见下表) 连接词 在名词性从句中的用法示例 要点提示 　 主语从句 宾语从句 表语从句 同位语从句 　 一 that That he left is certain. I knew (that) he had left. The fact is that he left. Ive no idea that he left. that没有意义，在从句中也不做任何成分，只起引导作用。 二 whether/if/as if/because/as Whether he left (or not) is unknown. I know who left. My question is who left. I have a question about who left. 有一定的词义，但不在从句中作语法成分。as if/because/as只引导标语从句。 三 关系代词：who, what, which, whose等以及加-ever构成的词 Who left is unknown. I know who left. My question is who left. I have a question about who left. 既有一定的语义、宾语、定语等成分。 关系副词：how, why, when, where等以及加-ever构成的词 When he left is unknown. Im uncertain when he left. What I wonder is when he left. I have no idea when he left. 既有一定的语义，又在从句中做状语。 2.引导名词从句的that和引导定语从句的that用法有何不同? 主要的差异有以下几点: ▲引导名词性从句的that没有语义,只起引导词的作用;引导定语从句的that指代先行词,有一定的语义。 That he was punished by his parents was a surprise.(名词性从句) All that I can do is to wait.(定语从句) ▲that 在名词性从句中不做任何语法成分,但在定语从句中可充当主语、宾语等。 That the 2000 Olympic Games will be held in Sydney is well known. The book （that） he is looking for just under his nose. （that 在定语从句中作look for 的宾语） ▲that 引导主语从句和同位语从句时不可省略,引导宾语从句和表语从句一般可以省略。引导定语从句的that在定语从句中作宾语时通常可以省略。 It is important that we should be there on time. Everything （that）he has are gone. 3.whether 和if 均可引导名词性从句,用法有什么不同? whether可以引导所有的名词性从句, if 只能引导宾语从句和位于句尾的主语从句。注意下列特殊情况。 ▲表语从句和同位语从句中只能用whether:The question is whether the film is worth seeing./ The news whether our team has won the match is unknown. ▲whether引导的主语从句可位于句首、句末,if 引导的主语从句只能位于句末:Whether we shall attend the meeting hasn’t been decided yet. ▲若宾语从句或位于句末的主语从句含有 or not