状语从句和定语从句分别怎么判断?最好举例说明!

1.定语从句：定语从句是由关系代词或关系副词引导的从句,其作用是作定语修饰主句的某个名词性成分,相当于形容词,所以又称为形容词性从句,一般紧跟在它所修饰的先行词后面.
2.关系词：引导定语从句的关联词称为关系词,关系词有关系代词和关系副词.关系代词有that,which,who,whom,whose,as等；关系副词有where,when,why等.关系词常有3个作用：1,引导定语从句.2,代替先行词.3,在定语从句中担当一个成分.
注：关系代词有主语.宾语之分.一般whom作为宾语.
4.定语：定语用来限定、修饰名词或代词的,是对名词或代词起修饰、限定作用的词、短语或句子,汉语中常用‘……的’表示.主要由形容词担任.此外,名词,代词,数词,分词,副词,不定式以及介词短语也可以来担任,也可以由一个句子来担任．单词作定语时通常放在它所修饰的词之前,作前置定语.短语和从句作定语时则放在所修饰的词之后,作后置定语.介词+关系代词引导的定语从句关系代词在定语从句中做介词宾语时
从句常由介词+关系代词引导
(1) The school (that/which) he once studied in is very famous.
(2) The school in which he once studied is very famous.
(3) Tomorrow I will bring here a magazine (that/which) you asked for.
(4) Tomorrow I will bring here a magazine for which you asked.
(5) We’ll go to hear the famous singer (whom/that/who) we have often talked about.
(6) We’ll go to hear the famous singer about whom we have often talked.
状语从句指句子用作状语时,起副词作用的句子.它可以修饰谓语、非谓语动词、定语、状语或整个句子.根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句.状语从句一般由连词(从属连词)引导,也可以由词组引起.从句位于句首或句中时通常用逗号与主句隔开,位于句尾时可以不用逗号隔开.
一般情况下,时间和条件状语从句的谓语动词一般用“一般现在时”表示“一般将来时”,用“现在完成时”表示“将来完成时”.例如：
I will call you as soon as I arrive in Beijing.我一到北京就给你打电话.（这是由as soon as引导的时间状语从句,从句中的谓语动词arrive是一般现在时,表示一般将来时,决不可用will arrive）
As soon as I have finished this work,I will go home.我一完成此工作,就回家.（从句中的谓语动词用现在完成时have finished,表示将来完成时,决不可用will have finished）
If he comes back,please let me know.如果他回来了,请通知我.（从句中的谓语动词用comes back,表示一般将来时,决不可用will come back）
状语从句讲解和练习
状语修饰动词、形容词、副词或整个句子.通常由副词、介词短语、动词不定式、分词和从句等担当.例如：
1.Naturally ,our grandparents were pleased to get our phone call .(副词)
2.We worked hard ,from sunrise to sunset .(介词状短语)
3.To help my disabled aunt ,I spend an hour working in her house every day .(不定式)
4.Seen from a distance ,the farmhouse looked deserted .(过去分词)
5.I know how to light a camp fire because I had done it before .（原因状语从句）
状语的位置比较灵活,可以位于句首、句末或句中.enough用作状语修饰形容词和副词时必须后置.
状语从句主要用来修饰主句或主句的谓语.一般可分为九大类,分别表示时间、地点、原因、目的、结果、条件、让步、比较和方式.尽管种类较多,但由于状语从句与汉语结构和用法相似,所以理解和掌握它并不难.状语从句的关键是要掌握引导不同状语从句的常用连接词