I am younger than you are.后面为什么跟着个are啊

I am younger than you are.后面为什么跟着个are啊 I am younger than you are 为什么加个are? i am younger than you are I am younger than you are是否是I am younger than you are young的 为什么要加are?I am younger than you are?请问这个are有什么用?已经有be动词了啊~ you are younger than I'm younger than you are. you are younger than I 还是you are younger than me? I am younger than you . he said ,you are younger than i 改为间接引语 you look younger than you really are He looks younger than you are?