本篇和我之前发的《极简英语语法，一图囊括所有》相呼应，是其中一个分支的详解。
简单句，是三种从句句型之一，在总图中的位置如下：
先行词：被定语从句修饰的名词，或代词，或句子
关系词：关系代词或关系副词，that ，which，who，whose等，指代先行词，在从句中充当成分。
从句：起描述或限定作用
他是需要帮助的人。
最简形式是简单句He is the man，从句who needs help作定语修饰the man。
你在网上买的书明天到
最简形式是 The book will arrive, 从句that your ordered online修饰the book作定语。
1.1 关系代词定语从句
1.1.1 关系代词特性
代替的先行词是人或物的名词或代词
在句中充当主语、宾语、定语等成分
关系代词在定语 从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
1.1.1 指人：who, whom, that, whose
He is the man who/that wants to see you.
The man whom I want to see is him.
She was the girl whom/that I saw in the restaurant.
A child whose father is lazy will be raised through widowed parenting. 有懒爸爸的孩子会被丧偶式育儿养大。
I, from whom you will learn a lot, is a self-employed person. 我，一个让你将来学会很多东西的人，是一名自由职业者。
You are no longer the man that you used to be. 你不再是吴下阿蒙。
1.1.2 指物: which, that, whose, of which
He lives in a villa whose history is longer than his father. 他住在一座年龄比他父亲还大的老别墅里
Above the the mountains are the clouds, whose exquisiteness is faithfully reflected by the lake. 山上有云，其精致被湖面忠诚地呈现。
This is the pen whose owner is a talented student. 就是这支笔，它的主人是学霸。
This is the pen (which) you want. 在从句中做宾语，可省略。
This ship in which we crossed the strait is broken. 我们乘坐过海峡的船是艘破船。
The picture which is taken by me is professional. 我拍出的照片很专业。
1.1.3 特殊用法
1.1.3.1 只能用that 不能用which
先行词为everything， anything，all，little，much等不定代词时；
Everything （that） the light touches is our kingdom. 凡阳光能照耀之地，便是我们的国度。
Is there anything that I can do for you?
Jenny told her mother all that had happened.
先行词被the only，the very，the same，the last修饰时；
The only thing I expect of you is to love, and be loved in return.
先行词被序数词或形容词最高级修饰时；
This is the most wonderful time that I have ever had.
This is the first time that she love a boy so deep.
先行词有人又有物时；
There are people and goods and plane that can be transported to the recipient 20 minutes after the plane was landed. 飞机运载的人和货物可在20分钟内被转运至接待处。
当主句是以who或which开头的特殊疑问句时。
Who is the girl that won the champion?
1.1.3.2 不能用that，只能用which
介词前置时；
This is the teacher the son of whom is a famous doctor. 这就是儿子是名医的那位老师。
China has many islands, the second largest of which is Hainan Island. 中国有很多岛屿，其中第二大的是海南岛。
Is that the new media for which you often write articles?这就是你经常投稿的新媒体吗？
非限定性定语从句中
先行词本身是that
The clock is that which tells the time，钟表是用来表示时间的。
The knife is that which is used to kill. 刀子是用来*戮的。
1.2 关系副词定语从句
1.2.1 where =at, in, on which
Beijing is the place where (in which) the capital of China is.
He want to find the place where he worked 10 years ago.
1.2.1 why=for which
This is the reason why (for which) he refused our offer.
I do not know the reason why he failed.
1.2.3 when=during, in, on which
By the time you arrive, we had waited for you for 2 hours. You are so late!
There are occasions when (on which) one must yield. 有时你不得不屈服。
I still remember the time when I met her for the first time. She was so young and so beautiful. 记得小苹初见，两重心字罗衣。
Every time when you go away, you take a piece of me with you. 歌词
2.1 限定性定语从句
2.1.1 特点
从句对被修饰的先行词有限定制约作用，使该词的含义更具体，更明确。
不能被省略，否则句意就不完整
大部分定语从句都是限定性的
2.2.2 例句
This is the boy you are looking for.
I lost my heart in the girl in which I fall in love last time.
She was the girl whom/that I saw in the restaurant.
Here is somebody who wants to speak to you.
2.2 非限定性定语从句
2.2.1 特点
解释说明作用
从句被省略后，句意完整
2.2.2 例句
I like singing for the very reason that(for which) she dislikes it. 我喜欢唱歌，基于同样的原因，她不喜欢。
He has a brother who works in Google. 他有个在谷歌工作的兄弟。（我们不知道他有几个兄弟，但是肯定有一个在谷歌工作，补充说明）
His wife, who loved him very much, went to see him. 他的妻子，爱他至深，赶过去看他。
An loquat tree in the yard, which I planted in the year my wife died, is like a canopy now. 庭有枇杷树,吾妻死之年所手植也,今已亭亭如盖矣
