高二英语总复习语法系列训练高二英语总复习语法系列训练名词性从句名词性从句（第二次演练）（第二次演练） English GrammarEnglish Grammar名词性从句名词性从句 名词性从句是由 if, whether, that 和各种疑问词充当连接词所引导的从句，其功能同名词一样。 一．主语从句一．主语从句 主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语 it 代替，而本身放在句子末尾。1. 1. It It 作形式主语和作形式主语和 itit 引导强调句的比较引导强调句的比较 It 作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。而 it 引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词 that 。被强调部分指人是也可用 who/whom 。例如： It is a pity that you didn’t go to see the film. It doesn’t interest me whether you succeed or not. It is in the morning that the murder took place. It is John that broke the window. 2. 2. 用用 it it 作形式主语的结构作形式主语的结构(1) It is ＋ 名词 ＋ 从句 It is a fact that … 事实是… It is an honor that … 非常荣幸 It is common knowledge that … 是常识(2) It is ＋ 形容词 ＋ 从句 It is natural that… 很自然… It is strange that… 奇怪的是…(3) It is ＋ 不及物动词 ＋ 从句 It seems that… 似乎… It happened that… 碰巧… It appears that… 似乎…(4) It ＋ 过去分词 ＋ 从句 It is reported that… 据报道… It has been proved that… 已证实… It is said that… 据说… 3. 3. 主语从句不可位于句首的五种情况：主语从句不可位于句首的五种情况：（ 1 ） if 引导的主语从句不可居于复合句句首。（ 2 ） It is said /reported… 结构中的主语从句不可提前。例如： It is said that President Jiang will visit our school next week. That President Jiang will visit our school next week is said. （ 3 ） It happens/occurs… 结构中的主语从句不可提前。例如： It occurred to him that he failed in the examination. That he failed in the examination occurred to...
