先写一个句子来作为讲解对象吧,如:the boy (who/that wears a pair of glasses )is my brother.
括号里的就是定语从句,用来修饰前面的先行词the boy.并且紧跟在先行词之后.它其实由两个句子组成即:the boy wears a pair of glasses和the boy is my brother组成.
找到相同的主语是the boy,句子的主体部分是the boy is my brother
再看这是一个什么样的boy呢?用一个句子修饰一下,由引导词who或者that来引导即who/that wears a pair of glasses.你是把那部分的顺序弄乱了呢?具体点.