英语作文开头非限制性定语从句【一】
当which引导的定语从句指代主句全部内容时，可以把which改为it，作形式主语，把原来的主句改成正在主语。或者把定语从句的整个信息改换为名词短语作主语，使原来的定语从句变成简单句。
例4： He indulges himself all day in computer games, which makes his parents extremely sad.
改为：It makes his parents extremely sad that he indulges himself all day in computer games.
他整天沉湎于电脑游戏，这使他父母伤心至极。(主语从句
或者：His indulgence in computer games all day makes his parents extremely sad. (名词短语
英语作文开头非限制性定语从句【二】
基本概念定语：用于修饰名词或代词的成分就叫定语。 定语从句：如果修饰某个名词或代词的定语是一个完整的句子，这个句子就叫定语从句。定语从句所修饰的名词或代词叫先行词。定语从句放在先行词后面。定语从句的引导：定语从句的引导词代替的是先行词。
1、当定语从句所修饰的名词是事、物时，用that/which引导，且that/which在定语从句中作主语或宾语。e.g:a.Thisisthepenthat/whichIboughtyesterday.
2.当定语从句所修饰的名词是人时用that/who引导，引导词再从句中做主语或宾语。
3.定语从句修饰的\'名词时地点时用which/that或where引导:若地点名词在定语从句中是作主语或宾语就用that/which引导，是作地点状语则用where引导，可与“介词+which”互换。作visited的宾语作介词in的宾语作work的地点状语
4.当定语从句修饰的名词是时间名词时：若在定语从句中作主语或宾语用that/which,作时间状语则用when,同样可与“介词+which”互换。
5.当定语从句所修饰的名词在定语从句中表示原因时用why。’tcomeisstillamystery.
6.当定语从句修饰的名词和引导词后面的那个词之间是所有关系时，用whose引导。女儿已经出国的那个人是位医生
7.一些特殊情况：
英语作文开头非限制性定语从句【三】
1：Peoples views onvary from person to person. Some hold thatHowever, others believe that
2：People may have different opinions on
3：Attitudes towards vary from person to person.==Different people hold different attitudes towards
4：There are different opinions among people as to
