ones 可以做代词， ones是复数 one's是“一个人的”（物主代词）ones必须和形容词连用。如果替代的名词时无形容词在前，则用some, any，而不 用ones。e.g.Have you bought any rulers? Yes，I 've bought some例：I have a story book,Tom has one,too. 这里one代表前面的story bookThere are a lot of apples,the red ones are sweet. 这里ones代表红苹果，不止一个One's mother's mother called grandmather. 一个人妈妈的妈妈叫外婆。这个应该是express one’s concern
