I.人称代词 a.用作人称代词，代替前文提到过的事物，以避免重复: b.也可以指动物或婴儿(未知性别的婴儿或孩子): 2.非人称代词 有时并不指具体的东西，可指天气、时间、距离、环境等 It was very quiet in the café.It is half an hour’s walk to the city. 3.指示代词 指代this或that This is your pen, isn’t it? What’s that on the desk? I guess it might be a robot.