The boy who is playing football is my cousin.

题目

The boy who is playing football is my cousin.
中,who is 可以省略吗?（比如：I don't know the boy playing football there.）

答案

可以省略,省略后意思一样,但是句子成分有所不同.
本来是定语从句.省略后就成了The boy playing football is my cousin
playing football 就是动名词作定语,而不是定语从句了