2023年初中英语语法学习之主语从句用法归纳

2023年初中英语语法学习之主语从句用法归纳 主语从句是在句子中充当主语的从句。　它与其它名词性从句一样，通常由连接代词或连接副词引导。 主语从句在复合句中作主句的主语,引导主语从句的词有从属连词that, whether以及连接代词who, what, which, whoever, whatever, whichever和连接副词when, where, why, how等. 例如: That she was chosen made us very happy. 她当选了使我们很高兴. What caused the accident is a complete mystery. 是什么导致了这次事故还完全是一个谜. Whether she will come or not is still a question. 她是否来还是一个问题. Which team will win the match is still unknown. 哪个队会赢得这场比赛还不知道. Whoever comes to the party will receive a present. 参加聚会的每一个人都将收到一份礼物. When they will start has not been decided yet. 他们何时出发还没决定. 注意:上述例句中的主语从句都是放在句首,但有时为了使句子结构平衡,避免"头重脚轻",常用it作形式主语,而把从句放在后面. 例如: It is a pity that she has made such a mistake. 她犯了这样一个错误,真是遗憾. It depends on the climate whether they are going shopping today. 他们是否今天去购物还得看天气情况. 1. 由that 引导的主语从句 That she lacks experience is obvious. 她缺少经验，这是显然的。 That you will win the medal seems unlikely. 你想获得奖牌看起来是不可能的。 That you are so indifferent bothers me. 你如此冷淡使我很烦恼。 2. 由连接代词引导的主语从句 What you need is more practice. 你需要的是更多的练习。 Which of them escaped from the prison is still a mystery. 他们哪一个是从监狱里逃跑的，仍然是个谜。 3. 由连接副词引导的主语从句 When they will come hasn't been made public. 他们什么时候来还没有公布。 Where she has gone is not known yet. 她去了哪儿，还不知道。 How the prisoner escaped is a mystery. 犯人是如何逃跑的是个迷。 Why he did it will remain a puzzle for ever. 为什么他做那件事将永远是个谜团。 4. 由whether引导的主语从句 Whether he will join us won't make too much difference. 他是否加入我们，没有太大的差别。 Whether she is coming or not doesn't matter too much. 她来不来都无关紧要。 5. 由 what 引导的主语从句 What she did is not yet known. 她干了什么尚不清楚。 What I want to know is this. 我想知道的就是这事。 What you need is more practice. 你所需要的是更多的训练。 6. 以it作形式主语的主语从句 1） it + be + 形容词 + 从句 It is doubtful whether she will be able to come. 她是否能来令人怀疑。 It is essential that he should be here by the weekend. 周末之前，他应该到这里是必要的。 It was clear (that) his words pleased her. 显然他的话使她很高兴。 2） it + be + 名词 + 从句 It is common knowledge that the whale is not a fish. 鲸鱼不是鱼，这是常识。 It is no surprise that Bob should have won the game. 鲍勃会赢得这场比赛，这不足为奇。 3） it + 动词 (+宾语或状语) + 从句 It does not interest me whether you go or not. 我对你去不去不感兴趣。 It shocked me that Peter did not tell anybody where he was. 让我吃惊的是彼得没有告诉任何人他在哪里。 It happened that she was out. 碰巧她外出了。 4） it + 动词的被动语态 + 从句 It is thought that he is the best player. 大家都认为他是最好的选手。 It is estimated that the vase is 2000 years old. ... ...