1.“someone”指一群人中的某个非具体的成员。“someone”比“somebody”更为正式。指不认识的人或通过名词提到的人。例如：
a. Will someone answer the phone, please?
请问有人接电话吗？
b. Someone will help you.
有人会帮助你。
c. Someone arrived at the meeting late.
有人开会迟到了。
2.“some one”是指我们从一群人或一组事物中选择的某个非具体的成员，重点在于圈定一组成员，再指其中某个成员。
需要记住一点，当我们使用“some one”的时候，后面往往接“of+名词短语”，或者在前面已有圈定这组选择的成员，否则，应当使用“someone”。例如：
a. Some one of the students was asking my question.
这群学生中有人正在问我问题。
b. We know that some one of the new robots has a defect, but we're not sure which.
我们知道一些新机器人有缺陷，但我们不确定是哪一个。
c. Presently her ear distinguished individual voices and she became aware that some one referred to scornfully as “that North guy” had kidnapped a waiter from a café in Cannes last night in order to saw him in two.
不一会儿，她的耳朵便分辨出了一个女子的声音，她说，就在昨晚，有一个被众人蔑称为“北方佬”的人，在Cannes的咖啡馆里绑架了一名服务员，预备将他锯为两半。
