elder与older的用法如何区分?

elder/older这两个词都是形容词old的比较级形式,区别在于:1)elder指“年长的”,常修饰人,用来表示出生顺序的前后和年龄的长幼,常作定语,不可用于than引导的比较状语从句。例如：The elder sister gave her little sister an apple。2)older指“年纪较大的,较老的,较旧的”,修饰人或物都行。既可作定语,也可作表语,可用于than引导的比较状语从句。例如：The older man in the photo is my grandfather。We work in an older building。Your bag is older than mine。