非限定性定语从句的作用是对所修饰的成分作进一步说明,通常是引导词和先行词之间用逗号隔开,将从句拿掉后其他部分仍可成立
Charles Smith,who was my former teacher,retired last year.查理·史密斯去年退休了,他曾经是我的老师.
这句就是非限制性定语从句,去掉 who was my former teacher后,句子的表意依然清楚
There is somebody here who wants to speak to you这里有人要和你说话,这句话是限制性定语从句,去掉who wants to speak to you后句子的表意就不清楚了.
有什么不懂再问吧