从句
一、定语从句¶
定语从句=形容词从句=关系从句
1. 思维方式¶
The rabbit is eating a carrot(先行词) that(关系词) I bought
在被修饰的词之后，添加另一个和它有关的词，再把新词放到另一个句子中，进行补充说明或逻辑阐述。
2. 构成¶
1.关系代词¶
that/who/whom/whose/which
The rabbit is eating a carrot that I bought. -> I bought the carrot.
The teacher who ate a carrot is a rabbit. -> the rabbit ate a rarrot
The teacher whom I saw yesterday is a rabbit. -> I saw the teacher yesterday.
The teacher whose favorite food is carrot is a rabbit. -> the teacher's favorite food is carrot.
The food which the teacher likes is carrot. -> the teacher likes the food
that vs. which
- 先行词是唯一的：that eg. The rabbit ate the largest carrot that I‘ve ever seen.
- 先行词是多选一的：which eg. The rabbit ate the carrot which(that) I bought.
2.关系副词¶
where/why/when
This was the place where the rabbit ate the carrot.
This is the reason thy the rabbit ate the carrot.
That was the day when the rabbit ate the carrot for the first time.
关系副词可转换为关系代词：where/why/when = at which/for which/on which
关系副词 = 介词 + 关系代词
3. 限定性和非限定性¶
1. 限定性¶
The rabbit ate the carrot which was on the table.
限定carrot的范围/性质
2. 非限定¶
The rabbit ate the carrot, which was on the table.
The rabbit ate the carrot, the carrot was on the table.
作插入语：
My head, which is big, is useful when it rains.
The biggest carrot, which the rabbit ate, was on the table.
代指整句话：
The rabbit ate the carrot, which was not surprising.
二、 名词从句¶
1. 主语从句¶
The fact is obvious.
句子主语由从句充当，要以引导词开头。
引导词：where, whether, when, how, who, that, what
That the rabbit ate a carrot is obvious.
Where the rabbit ate a carrot is obvious.
When the rabbit ate a carrot is obvious.
How the rabbit ate a carrot is obvious.
Who ate a carrot is obvious.
What the rabbit ate is obvious.
形式主语it
It is obvious that the rabbit ate a carrot.
It is obvious where the rabbit ate a carrot.
It is obvious when the rabbit ate a carrot.
It is obvious how the rabbit ate a carrot.
It is obvious who ate a carrot.
It is obvious what the rabbit ate.
2. 宾语从句¶
在整个复杂句中作宾语，包含确定/不确定信息
I saw that the rabbit ate a carrot.
I saw whether the rabbit ate a carrot.
I saw where the rabbit ate a carrot.
I saw when the rabbit ate a carrot.
I saw how the rabbit ate a carrot.
I saw who ate a carrot.
I saw what the rabbit ate.
1. that省略¶
宾语从句中的that往往可以省略
I know (that) the rabbit ate a carrot.
但引导词 who, what, which, when, where, how 不能省略
有时that也不能省略，否则会有歧义或者语法错误
I don't know that the rabbit ate a carrot and that you saw it.
I know, just like you do, that the rabbit ate the carrot.
2. 某些词后的宾语从句的否定¶
否定加在谓语动词前
I don't think that the rabbit is smart.
3. 主从时态一致¶
I don't think that you're right.
I knew that the rabbit liked carrots.
不变的客观现象例外：I knew that the sun rise in the east.
4. be + 形容词 + that¶
I am sure that there's a carrot on the table.
= confirm that
I am happy that there's a carrot on the table.
= like that
I am afraid that there's a carrot on the table.
= fear that
3. 表语从句¶
=主语补语从句 用从句充当系动词后的表语
系动词是be动词：
The problem is that the rabbit is hungry.
The reason is that there's the rabbit is hungry.
The question is whether the rabbit is hungry.
The question is what the rabbit should eat.
The question is where/when/how the rabbit should eat the carrot.
系动词非be动词：
It seems that the rabbit is hungry.
4. 同位语从句¶
同位语：用不同的方式把一个概念再说一遍，用逗号隔开
My teacher, Papa rabbit(同位语), likes carrots.
同位语从句：一个从句来充当同位语，长修饰抽象的名词
1.包含已知信息
The fact that the rabbit ate a rabbit did not surprise me.
2.包含未知信息
The question whether the rabbit will eat the carrot is on all our mind.
I have no idea who ate the carrot.