名词性从句

• 名词性从句
  • 主语从句
    • 用”it“作形式主语的主语从句
    • 主语从句的位置
    • 使用主语从句的注意事项：
  • 宾语从句
    • 宾语从句的位置
    • it 形式宾语 ➕ 宾从
  • 表语从句
    • 系动词的的分类
    • 表语从句的位置
  • 同位语从句
    • 同位语从句常见 抽象名词:
  • 名词性从句引导词
    • 名词性从句引导词的用法
      • 连接代词
      • 连接副词
      • whether 与 if 引导名词性从句是的区别
        • 考点
      • 关系连词的基本概念
      • 连接词 that 的省略问题
    • 名词性从句的解题步骤

主语从句

 在复合句中 充当主语的从句 叫主语从句。

• Jim is good at playing the piano.   (名词)
• To see is to believe.   (不定式)
• Somking is bad for health.   (动名词)
• What he has said is true.   (从句)

⚠️注意： 常用 it 代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。句型如下：

1. It ➕ be ➕ 名词 ➕ that从句
2. It ➕ be ➕ 形容词 ➕ that从句
3. It ➕ be ➕ 动词的过去分词 ➕ that从句
4. It ➕ 不及物动词 ➕ that从句

用”it“作形式主语的主语从句

1. It ➕ be ➕ 形容词(obvious, true, surprising, wonderful, possible, likely, certain) ➕ that从句
   • It is certain that he will win the match.
   • It isn't likely that I should accept such an offer as that.
2. It ➕ be ➕ 过去分词(said, reported, thought, expected, decided, announced, suggested等) ➕ that从句
   • It is reported that 20 people were killed in the accident.
3. It ➕ be ➕ 名词词组(a pity, a shame, good news, an honor, no wonder等) ➕ that从句
   • It is a fact that he cheated in the exam.
4. It ➕ 动词/动词短语(seem, appear, happen, matter, turn out, occur to, make no difference等) ➕ that从句
   • It seems that he is not himself today.
   • It suddenly occurred to her that Joe was afraid of being alone.

★主语从句中用来表示 惊奇、不相信、惋惜、理应如此 等语气时，
谓语动词用 虚拟语气 “（should）➕ 动词原形”，常用句型有：
🔶 It is necessary/ important/ surprising/ strange/ natural等 ➕ that从句
🔶 It is suggested/ requested/ desired/ ordered/ demanded等 ➕ that从句

• It is necessary that we (should) have breakfast.
• It was suggested that we (should) put off the meeting.

主语从句的位置

前：主语从句 ➕ 谓语动词 / 系动词
后：It ➕ 其他成分 ➕ 主语从句

使用主语从句的注意事项：

1. 规律一：主语从句_{(名词性从句)}一律用陈述语序，即 主语在前，谓语在后。
   • When will he come is not known. ❌
   • When he will come is not known. ⭕️
2. 规律二：连词 that 在主语从句中无实际意义，但不能省略。
   • He will not come to the meeting this evening is true.
   • That he will not come to the meeting this evening is true.
3. 规律三：主语从句的谓语动词多用 单数第三人称 形式。
   • When he was born are a puzzle. ❌
   • When he was born is a puzzle. ⭕ ️
   • When they will start and where they will go are still unknown. ⭕️

宾语从句

1. I want to know why the book is popular among college students.
2. I am thinking of whether I can have time travel.
3. I am sure that the book will provide you with deep insights.
4. I think it necessary that humans continue to explore the universe.

宾语从句的位置

• 动 ➕ 宾从：主语 ➕ 谓语(vt.) ➕ 宾语从句
• 介 ➕ 宾从：主语 ➕ 谓语(vi.) ➕ 介词 ➕ 宾语从句
• 形 ➕ 宾从：I am_系 sure_adj ➕ 宾语从句
• it ➕ 宾从：I think it _形式宾语 ➕ necessary等 ➕ 宾语从句

it 形式宾语 ➕ 宾从

常见结构总结

1. think/ find/ feel/ consider/ make/ regard... ➕ it ➕ 形容词/名词 ➕从句
2. hate it ➕ 从句
3. depend on it ➕ 从句

  在复合句中 作宾语的名词性从句叫做宾语从句，位于及物动词（短语）、介词或形容词之后。

• We must never think (that) we are good in everything while others are good in nothing.
• Everything depends on whether we have enough money.
• She will give whoever needs help a warm support.

⚠️注意： 在可以接复合宾语的动词之后，如 think、make、consider等，可以用 it作形式宾语。

表语从句

  在复合句中 作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，有时用 as if，because 等引导。其基本结构为：主语 ➕ 系动词 ➕ 从句

1. The fact is that we have lost the game.
2. That is why he didn't come to the meeting.
3. It looks as if it is going to rain.

⚠️注意： 当主语时 reason 时，表语从句要用 that 引导而不是 because。

• The reason why he was late was that he missed the train by one minute this morning.

系动词的的分类

1. (动)变化类：become, grow, turn, get, go, fall
2. (静)静止类：be, keep, stay, remain
3. (人)感官类：look, sound, smell, taste, feel
4. (定)判定类：seem, appear, prove, turn out

表语从句的位置

主语 ➕ 系动词_{(主要为be)} ➕ 表语从句

同位语从句

同位语从句：解释名词内容的句子

We must accept the fact that we are defeated in the game.
	         被解释的词  		同位语从句

同位语从句常见 抽象名词:

1. 消息类：news、message、information、notice、word…
2. 事实类：fact、truth、reality、evidence…
3. 观点类：view、opinion、idea、point…
4. 建议命令：advice、suggestion、command、order、recommendation、requirement、demand、request ➕（should）➕ 动原
5. 其他类：doubt、chance、possibility、hope、wish…

名词性从句引导词

1. 连接代词： who, whom, which, whose, what, whoever, whomever, whichever, whatever
2. 连接副词： when, where, why, how
3. 关系连词： whether, if, as if, as though, because, that

名词性从句引导词的用法

连接代词

1. who: “谁”、作主语、起连接作用
   • Who will go to the college is still uncertain.
2. whom: “谁”、作宾语、起连接作用
   • Whom you will learn from is worth thinking over.
3. which: “哪…”、作定语、起连接作用
   • Which class is suitable for us isn't most important.
4. what: “事情”、作主表宾、起连接作用
   • What I desire to get is a good reputation.
   • ⚠️注意：who/whom在从句中不做表语
5. whose: “谁的”、作定语、起连接作用
   • Whose bag was the most beautiful is still unknown now.
6. whoever: “…的任何人”、作主语、起连接作用
   • Whoever could solve the problem will be rewarded.
7. whomever: “…的任何人”、作宾语、起连接作用
   • Whomeever you will meet in the meeting is excellent.
8. whatever: “…的任何东西”、作主表宾
   • Whatever you did in the past was very meaningful.
9. whichever: “…的那些或那个”、作主表宾
   • Whichever team win the game is possible.

连接副词

⚠️ 使用前提：句子有 主谓/主谓宾/主系表，在从句中做状语

1. when: “什么时候”、作状语、起连接作用
   • When the meeting will begin isn't decided now.
2. how: “如何”、作状语、起连接作用
   • How the thief stole the bike is still a mystery.
3. where: “什么地方”、作状语、起连接作用
   • Where I could buy the book is uncertain now.
4. why: “为什么”、作状语、起连接作用
   • Why he killed himself is still a secret now.

⚠️注意： 在从句中不做句子主干，做 状语，提供 “意思”。

whether 与 if 引导名词性从句是的区别

1. 主语从句、表语从句、同位语从句 中只能用 whether，不能用 if。
   • Whether the meeting will be put off has not been decided yet.
   • The trouble is whether he can come on time.
2. 宾语从句 中 whether 和 if 一般可以互换，但：
   1. 作介词宾语是连词一般用 whether。
      • It all depends on whether he will recover.
   2. 后面直接跟 or/or not 时用 whether。
      • I don't know whether he will take part in the meeting or not.

考点

doubt, question: 用于 肯定结构 时，后面用 whether 引导名词性从句；
                 用于 否定结构或疑问结构 时，后面用 that 引导名词性从句。
be sure: 用于 肯定句或疑问句 时，后面接 that 引导的名词性从句；
         用于 否定句 时，后面接 whether/if 引导的名词性从句。

1. I have no question that he will succeed.
2. The question came up at the meeting whether we had enough money for our research.
3. I don't doubt that he'll come.

关系连词的基本概念

1. because: 连接从句，不做“主干”，表示“因为”
   • – Why are your eyes filled with tears?
     – That is because the exam is so difficult.
2. that: 连接从句，不做“主干”，没有“意思”。
   • That the CCVID-19 vaccine was developed succeffully excited all of us.
   • ⚠️注意: 只有 在宾语从句总可以省略，主从、表从、同从中 不能省略。
3. as if/though: 连接从句，不做“主干”，表示“似乎/好像”
   • It seems as if she knows everything.
   • It sounds as though you are from the south of the nation

连接词 that 的省略问题

  在主语从句、表语从句和同位语从句中，连接词 that 不能省略。
  只有 宾语从句 中的连接词 that 可以省略，但在以下几种情况中 that 也 不能省略：

  A.当 that 从句和主句谓语动词之间有插入词语或者从句主语之间有插入语时，that 不可省略。

• He judged that, because he was a child, he did not understand.

  B.当两个名词性从句并列作宾语时，后面的 that 不能省略。

• Everyone knew what happened and that she was worried.

  C.当 that 作介词宾语时，that 不可省略。

• The reason liew in that she works harder than the others do.

名词性从句的解题步骤