除了关系代词that外,所有的关系词都可以引导非限定性定语从句,举例如下：
Last night,I saw a very good film,which was about the Long March.昨晚我看了一部非常好的电影,那是关于长征的.
This letter is from my sister,who is working at a factory now.这封信是我姐姐寄来的,他现在在一家工厂上班.
I paid a visit to compony last month,where my brother are working.上个月我参观了一家公司,我哥哥在那里工作.
My grandpa's childhood is bitter,when he lived a hard life.我祖父的童年是辛酸的,那时候他过着十分艰难的日子.