什么是定语从句
从句——句子充当一个成分——句子做定语——定语从句
A lovely boy——lovely 是定语
一个（有着白皙的脸和帅气的头发）的男孩
英语会先写核心再写修饰——A boy with a fair face and handsome hair
定语从句：修饰名词代词的从句
先行项：被定语从句修饰的词或句子
关系词：引导定语从句的词
名词性从句：that,which,what,if,whether,who关系词
代词:
that, which, who, whom, whose, as.
关系副词有:
when,where，why
没有how,what； as可能是介词、可能是连词：当……的时候，因为，尽管；定从代指前面的内容定从三步走：确定先行词，选关系词，写出从句。
先行词=关系词，表示一样的事物限定性定语从句
关系代词
当先行项是人时
关系代词用who/that/whom
在介词之后只能用whom（因为whom是宾格，介词+代词宾格）
who/that指人，在从句中作主语
我是女生，爱哭的女生。
I am a girl who likes vrying（who是主语，who=girl,是三单，所以谓语动词like+s）
我是女生，你不懂女生。
I am a girl who you don't understand.(who是宾语）
注意！
the girl who's moved into my heart.（不完整）——那个让我心动的女孩，缺少主干。
写句子时注意别只写从句。
阅读题：定从——有谓语——后面又有谓语——可能是主句的谓语。
1.whom/who/that指人，在从句中做宾语,可省略（做主语不可省略）
2介词之后只能用whom。
The child . (whom/who) the doctor looked at was afraid.
——为什么有at可以用who，因为要at whom这样才算 (介词在前面）
Zhang Yixing is the man to whom many girls want to marry.（前面有to），marry to 嫁给……
先行词是物
1.关系代词用which/that
2.介词之后只能用which
（that可以指人，也可以指物，当介词提前时不可以用）
Enoki is a kind of food!. It is hard to digest.
Enoki is a kind of food which/that is hard to digest.（which/that是从句主语）
金针菇是一种很难消化的食物。（把重复的it换成了which/that)
只用that的情况
1、先行词是不定代词时。
不定代词指不一定指的是谁：some,any,no,every one,thing,body （自由组合some one,some thing…）特殊：neither none either
Is there anything that I can do for you ? 我能为您做点什么? anything只能用that。
2、先行词被序数词和最高级修饰时。
（the first,second,third; the est ） +that
French is the most difficult language that I have learnt.法语是我学过的最难的语言。
Japanese is the easiest language that I have learnt. 日语是我学过的最简单的语言。
3.先行词被the only, the very, the last修饰时
You were the last man in the world (that) I could ever marry.
全世界男人都死光了，我也不会嫁给你的。——That是marry的宾语
Her opinion is the only one that matters. 她是唯一一-个说了算的。
matters=is important that=opinion 观点
This is the very bed that I have been looking for. 这就是我一直以来寻找的床。
先行词是bed that=bed that I have been looking for 修饰 bed
whose
表示所属，谁的
The second generation of star(星二代）are young people whose parents are famous stars.
（whose 做 parents 的定语，必须充当成分。whose = young people）
The buildings whose names are strange are located in Beijing. 这些名字很奇怪的建筑坐落于北京。
（whose names are strange修饰 buildings ，whose就是建筑的，whose不能换that，which,它们没有所属意思。）
关系副词
when,where,why
1. where 先行词是地点，在从句中作地点状语。
where=地点，做地点状语。（when-时间，时间状语；why-原因，原因状语）
This is the city.
I was born in the city (there)
This is the city where I was born. 这是我出生的那座城市。
(This is the city是地点，where是地点状语，后面 I was born 是主谓结构，缺状语。）
just like kidding your father（坑爹）is a situation where someone is cheated or made fun of.
situation（状态，情况）——英语中属于地点，还有condition,case。
someone is cheated or made fun of.某人被欺骗或被取笑，是被动语态。someone是主语。
2. when
先行词是时间，一在从句中作时间状语
她永远也不会忘了结婚那天。
She'll never forget the day when they got married.
（ the day ——先行词，they got married主谓齐全，when是时间状语）
The Spring Festival is a time （when people put on weight）.
3.why
先行词是原因，在从句中作原因状语
我学努力语法的原因是我想成为更优秀的人。
The reason (why I study grammar hard) is that Iwant to became a better person.
前面是定语从句，I study grammar hard主谓宾完整，why是时间状语。后面that是表语从句
写作句型：The reason……why……that… ….之所.....的原因.....
如何选关系词？
1、看先行词是什么
人：who,that,whom,whose
物：which,that
地点：where
时间：when
原因：why
2、看定语从句缺什么
不缺主干：关系副词
缺主语、宾语：关系代词
判断以下句子的正误
1、That was the reason why he gave me yesterday.
2、That was the reason which he gave me a note yesterday.
第二个是正确的，give sb sth,第一个没有sth.第二句which 做宾语（从句缺宾语）
这就是他昨天给我一张纸条的原因。
1、 will never forget the day that Michael Jackson died.
2、I will never forget the day when I spent with Mr. Bean.
第一句，Michael Jackson是主语，died是不及物动词，that不能做成分，改为that。
第二句， spent是及物动词，及物动词要加宾语， when改为that或删去。
非限制性定语从句
非限制定语从句，就是不限制，没有它也是可以的。
. 限制性定语从句，第三个女孩中喜欢其中一个：I like the girl who is making a“yeah".
非限制性定语从句：一个女孩中选择：I like the girl, who is making a“yeah".（补充说明，分开解释）
非限制定语常使用情况
1、专有名词
当先行词时，后面必须用非限制性定语从句
They climbed to the top of Mount Tai, where they enjoyed the view of sunrise.
他们爬上了泰山的山顶，在那里他们欣赏了日出的景色。they enjoyed the view of sunrise，用地点状语where。
2、类指
A bear, which is always described as awkward, is actually quick in action.
通常被描述为笨拙的熊，实际上行动迅速。A bear,一类，指熊类。
3、先行词是句子
限制性定语从句与非限制性定语从句
形式上：限制 没有逗号，非限制 有；作用：限制 修饰限定，非限制 补充解释；限制不能省略，非限制能省略；限制性翻译：……的；非限制性：另起一句。（that不能引导非限制）
Her brother who is now a soldier always encourages her to go to college.
她当兵的那个哥哥总是鼓励她.上大学。(她还有其他哥哥。)
Her brother, who is now a soldier, always encourages her to go to college.
她哥哥总是鼓励她.上大学，他是当兵的。(她只有一个哥哥。)
标签：定语,21,whose,who,从句,状语,where From： https://www.cnblogs.com/55zjc/p/16650254.html