只要是疑问代词就可以充当介词宾语。疑问代词包括 whom(口语中可以who代替)、what 和which 三个。例如: Who(m) are you looking for? 你在找谁? What does he look at? 他瞧什么? Which of the books are you fond of? 你喜欢那一本书?