This is Mr. Zhang，whose daughter I love very much.

这是张先生，我很爱他的女儿。

“familiar”熟悉的

This is Mr. Zhang，whose daughter I’m familiar with.

这是张先生，他的女儿我很熟悉。

“content”内容

I just bought a book whose content is interesting.

I just bought a book，the content of which is interesting.

我买了一本书，内容十分有趣。