1、定语从句中修饰人时，that 和 who 的选择who，that 在很多情况下可以通用，但是有些情况只能用 who:1. 先行词是 one, ones, anyone 的时候宜用 who.One who has nothing to fear for oneself dares to tell the truth.The ones who flatter me dont please me.Dont tell anyone about the news who oughtnt to know it.Anyone who fails to finish the task given should
2、 be criticized.2. 先行词为 those 的时候，宜用 who 为关系代词Those who were not fit for their work could not see the beautiful clothesmade of the magic cloth.Those who want to go to the Great Wall sign up here.3. 当先行词有比较长的后置定语的时候I met a foreigner in the street yesterday who could asked me questions inChinese.4. 一个句子中带有两个定语从句，其中一个定语从句的关系代词 为 that,另一个则用who.The boy that you met last night is the group leader who studies very hard.5. 在 there be 开头的句子中There is an old man who wants to see you.There are many young men who are against him.一般没有只能用 that 不能用 who 的情况，能用 that 的句子，也能用 who
