一 定语从句：定语从句的介绍
就像是一个形容词或介词短语修饰名词一样，定语从句也可以修饰名词。定语从句所修饰的名词称为先行词。
形容词：The green team
介词短语：The team in green
定语从句：The team who were wearing green
定语从句通常由关系代词来引导，如which, that, who, whom, whose,或关系副词来引导，如when, where, why。关系代词可以在定语从句中担当主语，宾语，表语，定语；关系副词可以在定语从句中担当状语。
如：做主语The trees which are on the school campus have lost their leaves.
做宾语The student whom we saw just now is the best runner in our school.
做表语Jack is no longer the lazy boy that he used to be.
做定语She has a brother whose name I can’t remember.
做状语The school where he studied is in Shenzhen.
二 定语从句：关系代词：that，which，who，whom，和whose
在定语从句中，that和which用来指代物。
如：This is the story that /which we wrote for our storytelling contest.
在定语从句中，who 用来指代人。
如：I am going to see a friend who has just come back from the UK.
当who在定语从句中做宾语时，可以用whom来取代，且whom比who更正式。
如：I don’t know the name of the teacher who/whom I saw in the computer room the other day. 当关系代词在定语从句中做宾语时，who，whom，which和that可以被省略。
如：He likes all the birthday presents(that/which)his friends gave him.
Whose用来表示所属，它既可指人也可指物。
如：I sat next to a girl whose name was Diane.
The club whose members are music fans meet in the school garden every Saturday afternoon.
一 定语从句：介词提前的定语从句 （preposition＋which; preposition＋whom）
当关系代词（which/whom）做定语从句中介词的宾语时，可以把介词提到关系代词的前面。 如：We thought you were a person from whom we could expect good decisions.
在非正式英语中，介词通常放在定语从句的最后。
如：Art is the subject which I know little about.
如果介词放在定语从句的最后，which 可以被that取代，whom可以被that和who取代。 如：Dad is a person whom/that/who I can easily talk to.
当关系代词做定语从句中介词的宾语，并且介词又放在定语从句的末尾时，我们通常省略关系代词who和that。
如：The topic (which) Eric is interested in is Physics.
Daniel is the person (whom) I want to make friends with.
当先行词是way时，我们用in which或that来引导定语从句，这种情况下，in which或that 可以被省略。
如：I didn’t like the way (that /in which) she talked to me.
二 定语从句：关系副词：when，where， why
1．我们通常用关系副词when 引导先行词是time，moment，day， season，year 等的定语从句。
如：Do you remember the day when we left you in charge?
