高考英语语法复习 名词性从句之主语从句学案

主语从句 1．that引导的主语从句 1． 概念： 在句子中担当主语的是一个从句，这个从句就叫做主语从句． that 引导主语从句，只起连词的作用，在从句中不起语法功能，即不作任何成分，也不含有任何意义，引导主语从句不可省略，故称："三不"． 2．用法： 1）that在句中不做成分．当主语从句位于句首时，不能省略： That he likes books of this kind is very interesting．＝ It's very interesting （that）he likes books of this kind． 这是用的最多的一种主语从句，但把这种主语从句放在句首是很少的，只是为了强调或谓语较长时才这样安排．例如： That prices will go up is certain． That she is still alive is a consolation． 2）当谓语动词是seem，appear，be a pity．be a wonder，be likely等时，使用形式主语It，而将真正的主语放在句尾，这时从属连词that可省略：It appeared to scientists on earth （that） the stars had moved． 还有一些例如：绝大部分主语从句都借助先行主语放到句子后部去． a．It +be + 形容词+that从句： It is natural that they should have different views． It was quite obvious that she didn't want to come． b．It +be + 名词 +that 从句： It's a shame that you're sick． It's a pity that he can't swim． c．It + 动词（+ 宾语或状语）+ that 从句： It happened that she wasn't in that day． It seems that you're right． d．It + 动词的被动语态 + that 从句： It's said that there has been an earthquake in India． It's reported that the enemy troops have crossed the border． 2．whether引导的主语从句 1．概念 如果一个句子在复合句中充当一个主语，那么这个句子就是主语从句． whether引导主语从句，只起连词的作用，在从句中不起语法功能，即不作任何成分，作是否的意思． 2．特点 1）whether 既可以引导主语从句也可以引导宾语从句，但if一般不能引导主语从句；whether 后面可以加or not， 而if 一般不与or not 连用．Whether or not she'll come isn't clear．她是否来还不清楚．此处whether引导主语从句． Whether he will go there has been decided． Whether he will leave the city has not been known yet． 2）在使用形式主语It，而将真正的主语放在句尾，可以用whether It's doubtful whether you are really to love the girl． It was a question whether the girl should get married． 3．wh-引导的主语从句 1． 概念： 在句子中担当主语的是一个从句，这个从句就叫做主语从句． 引导主语从句的wh﹣疑问词有：what， which， who/whom， whose， when， where和why．这些疑问词引导主语从句时，在从句中作主语． 2． 用法： 1）连词代词what， who， which， whose等引导的主语从句．这些连接代词作用相当于代词，在从句中担当主语、宾语、表语、定语等． What we need is more time．  我们需要的是更多时间 Who was responsible for the accident is not yet clear． 谁应该对这场事故负责还不清楚． Whose book it is not important．   这是谁的书并不重要． Which school you want to go matters much．  你想去哪所学校很重要 2）连接副词when， where， why， how引导的主语从句．这些连接副词相