1.只指人，并且在从句中作主语的情况
A.The man who is a new one has rent a flat in downtown of New York for a long time.新来的这个人在纽约市中心租了一栋公寓，有一段时间了。（the man 指人并在句中作主语）
B.The girl who has looked for a job with the help of her tutor is fortunate.这个女孩在导师的帮助下找到了一份工作，她是幸运的`。（the girl 指人并在句中作主语）
C.The professor who wrote a book is teaching history.写这本书的专家正在教历史。（the professor既指人又在句中作主语）
2.在非限定性定语从句中作主语，并指人时
A.He feel honored to work with Mr.Li, who has good reputation in the business.他感到很荣幸和李先生一起工作，李先生在业界有着良好的声誉。
B.Where is the girl, who was the witness in the severe accident.作为这场严重车祸的目击者的这个女孩在哪？
C.The scientists, who invented a kind of immune medicine.科学家发明了一种免疫性的药物。
3.先行词是god, angel,fairy等词时，用who不用that。
A.In the oil painting, the state of angels who smiled at each other delivered the artist`s emotional.在油画中，天使互相微笑的状态传递了艺术家的情感。