关于it is not until 的强调句

问题描述:

关于it is not until 的强调句
是否有it is not until +句子+who………… 的句子?给个例子,跟人争辩呢!
我知道可以加that 但我现在想知道可不可以接who

有,是强调句加定语从句:It was not until 10:00 pm when I finally finished my work that I was able to meet my friend John,who had been waiting to see me 这是一个强调句,里面有两个从句.说是什么从句?