名词性从句重点难点解析讲解与练习 主语从句 做主语，用that，whether，what（＝the thing that）等连接词（原疑问词）引导 宾语从句 做宾语，用that（可省略），if，whether（or not），what（＝the thing which）等连接词（原疑问词）引导 表语从句 用that（一般不省略），whether，what（＝the thing which）等连接词（原疑问词）引导 同位语从句 用that（常用在news，thought，idea等词后），whether等连接词（原疑问词）引导 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。如： Who will go is not important. It doesn’t matter so much whether you will come or not. That he suddenly fell ill last week made us surprised. 1. It 作形式主语和it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.（主语从句）     It doesn’t interest me whether you succeed or not. （主语从句） 语法易错题 英语单词快速记忆 高中英语课本     It is in the morning that the murder took place.（强调句）     It is John that broke the window. （强调句） 2. 用it 作形式主语的结构： 句型   例子 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. 主语从句不可位于句首的五种情况：        情况说明 例句 1 if 引导的主语从句不可居于复合句句首。 If he will come or not is unknown        （误） . Whether he will come or not is unknown  （正） 2 It is said /reported…结构中的主语从句不可提前 It is said that Jiang will visit our school.    （正） Jiang will visit our school next week is said. （误） 3 It happens/occurs…结构中的主语从句不可提前 It occurred to him that he failed in the examination. （正） That he failed in the examination occurred to him. （误） 4 It doesn’t matter how/whether …结构中的主语从句不可提前 It doesn’t matter whether he is wrong or not. （正） Whether he is wrong or not doesn’t matter. （误） 5 含主语从句的复合句是疑问句时，主语从句不可提前 Is it likely that it will rain in the evening? （正） Is that will rain in the evening likely? （误） 用适当的连词填空： 1. I can’t decide ____________ dictionary I should buy. 2. That’s ____________ he refused my invitation. 3. I am very interested in ____________ he has improved his pronunciation in such a short time. 4. ____________ we need is more time. 5. The fact ____________ she had not said anything at the meeting surprised everybody. 6. ____________ and ____________ they will meet has not been decided yet. 7. Please tell me ____________ you are waiting for. 8. Is that ____________ you are looking for? 9. Would you please tell me ____________ the nearest post office is? 10. I don’t know ____________ he will agree to the plan or not. 答案： 1. which; 2. why; 3. how; 4. What; 5. that; 6. when, where; 7. who(m); 8. what; 9. where; 10. whether/ if