He is an older boy than me.Shanghai is a bigger city than *.这两个句子对吗

对啊

错的，应该是 He is older than me . Shanghai is bigger than *.

如果想用这种句式的话 ：He is the boy who is older than me .Shanghai is city which is bigger than *.He is older than me .Shanghai is bigger than *.直接这样说就可以的 不用加boy city等...

可以。