非限制性定语从句有时形式上是从句，实质上其功用相当于一个并列的分句。如：
He said he had no money, which was not true. 他说他没有钱，这不是实话。(which相当于but it)
Then he met Mary, who invited him to a party. 后来他遇到玛丽，玛丽邀请他去参加晚会。(who相当于and she)
My father may have to go into hospital, in which case won’t be going on holiday. 我父亲可能需要住院，如果那样他就不去度假了。(in which case相当于and in that case)