关于限定词,副助词、代词和后置修饰语的语法问题

问题描述:

关于限定词,副助词、代词和后置修饰语的语法问题
I’m buying two of them.(Context:You and a friend enter a sporting goods shop and
your friend says this to you,pointing to a rack of socks)
现在在学限定词,副助词、代词和后置修饰语.这句话有这方面的问题么?

I’m buying two of them.(Context:You and a friend enter a sporting goods shop andyour friend says this to you,pointing to a rack of socks) .这句话没有这方面的问题 但two可以用 two pairsthem改成those呢因为我主要在学关于限定词,副助词、代词和后置修饰语them代替的是a rack of socks

所以them不能改成those ,因为这是第二次提到

of them是介词短语 作后置定语