所有的名词性从句均不能用逗号分开，并且它们都用相同的关联词，关联词如下： ① 主从连词：that (无意义), whether (是否), if (是否)（在句子中不充当任何成分） ② 连接代词：who (谁), whom (谁), whose (谁的), what (什么), which (哪一个) ③ 连接副词：when (什么时候), where (什么地方), how (怎样), why (为什么)
如： Even in comic books where(=in which) there are no words, the stories are fully expressed through the drawings. No one knows the reason why (= for which ) he was so angry that day.
地点状语从句：引导地点状语从句的连词是where,wherever. Wherever she went,she took her little daughter with her.
原因、结果和目的状语从句： 1）引导原因状语从句的从属连词有：because,as,since,now(that),seeing that,considering that,in that等。 Considering that he is a freshman,we must say he is doing well.
2)引导结果状语从句的连词有：so...that,such...that ,so that,that,so等。 Mickey Mouse is so attractive that the children are reluctant to leave.
3)引导目的状语从句的连词有：so that,in order that,for fear that,lest等，从句常使用may,might,can,could,would等情态动词。 We got up early this morning so that we could catch the first bus to the railway station.
条件和让步状语从句： 1）引导条件状语从句的连词和词组有if,unless,as(so) long as,on condition that,in case,provided(providing) that,supposing等。 As long as you have the right equipment,you can use a telephone line to transmit computer data.
2)引导让步状语从句的连词和词组有though,although,whether,even though,even if,no matter what (when, how...), whatever( whenever, wherever, however....)等。though,even if等引导状语从句可转换成含有as的部分倒装结构，具有强调意义。其结构为“形容词（副词、动词、名词）+as+主语+谓语”。 No matter what you may say,I would not change my mind. Young as he is,he is quite experienced in this work.(=though he is young)
如： ■他什么时候离开，现在还不知道。 误：When will he leave is not known yet. 正：When he will leave is not known yet. 析：when在此引导主语从句，要用陈述句词序，不能用疑问句词序。 ■我记不起他是什么样子了。 误：I don’t remember what did he look like. 正：I don’t remember what he looked like. 析：what在此引导宾语从句，要用陈述句词序。