英语九年级【知识精讲】13.句法(18)名词性从句——主语从句 课件

这是一份英语九年级【知识精讲】13.句法(18)名词性从句——主语从句 课件，共18页。PPT课件主要包含了主语从句定义，主语从句三要素，从句语序，谓语动词常用单数，引导词，陈述语序先主后谓，主语从句引导词，主语从句的考查难点，答案B等内容，欢迎下载使用。

观察以下句子，注意主语从句的特点：1. That the earth travels rund the sun is a well-knwn fact.2. Whether the artist can d it r nt is uncertain.3. Why he did it remains a mystery.4. Whever breaks the law will be punished.在复合句中充当主语成分的句子叫做主语从句。
1. What he said makes me sad.2. Why he made s many mistakes is nt clear.
主语从句引导词的选择主要是根据从句的结构和意义来选择：从属连词：that, whether连接代词：wh(ever), which(ever), what(ever)连接副词：where(ever), when(ever), why, hw
1. 连接词：that/whether如果从句的意义和结构完整，则选用that或whether。that本身没有意义，不作句子成分，只表示从句的开始，位于句首时，that不能省略。whether表示 “是否”，不作句子成分，位于句首。1) That peple cut dwn t many trees destryed the balance f nature.2) Whether we will g camping tmrrw depends n the weather.
2. 连接代词：wh, which, what, whse, whm, whever / whichever /whatever在主语从句中不含有疑问意义。如果从句的意义和结构不完整，根据从句的意义和结构选择相应的连接代词。连接代词在从句中起名词性作用，担当一定成分（主语、宾语、表语等）。
1. Wh will take part in the meeting has nt been decided.2. Which student will win the first is uncertain.3. What I can’t understand is why he has changed his mind.4. Whever fails t see this will make a mistake.5. Whatever was said here must be kept secret.
3. 连接副词：where(ever), when(ever), why, hw连接副词when, where, why, hw在从句中作（时间、地点、原因、方式）状语。1) Where we shuld leave it is a prblem.2) When he will be back depends n the weather.3) Hw this happened is nt clear t anyne.
主语从句有时为了使句子结构平衡，避免句子“头重脚轻”，常用it作形式主语代替主语从句，放于句首，而把真正的主语（即主语从句）置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：（1）It + be + 名词 + that从句. 名词有(n wnder, a pity, a fact, a shame, gd news, a surprise…)
1. ___________（遗憾的是）that we lst the game.2. _____________ （惊奇的是）that he cheated in the exam.3. __________ （事实是）that English is being accepted as an internatinal language.
It is a pity
It is a surprise
It is a fact
（2）It + be + 形容词 + that从句. 形容词有(true, natural, gd, wnderful, funny, pssible, certain, necessary, imprtant…) 1. _____________（有必要） that an efficient wrker (shuld) finish his wrk n time.2. _____________（重要的是）that yu (shuld) think befre yu say r d anything.
It is necessary
It is imprtant
在含有一个 “imprtant重要的/necessary有必要的”之类的形容词的结构中，从句应当用“ …+that+主语+(shuld)+动词原形”形式（shuld常省略，而直接接动词原形）。
_______ surprised me mst was that such a little by f seven culd play the vilin s well.A. ThatB. WhatC. WhetherD. When
It is necessary that a cllege student _______ at least a freign language. A. mastersB. shuld masterC. masteredD. will master