you are on your own,on your own是adv,为什么be后面可以加adv?

问题描述:

you are on your own,on your own是adv,为什么be后面可以加adv?
+ =.语法学得好烂求指导

on one's own 整体是【介词短语】,在句子中作表语.
祝你开心如意!