意为“一个人其中一个”时,one为名词,可做主语谓语动词用单数:There are 2 children in the yard.One is running , and the other one is chasing behind him.因为主谓语单复数形式要一致
而one作数词修饰名词时就另当别论,路more than one+单复数名词,需要的话我会进行补充