1） 人称代词主格的用法
① 作主语 e.g. I’m a student. You are a teacher. We all work very hard.
② 作表语，用在“It’… who(that)…”结构中 e.g. It’s she who has been wrong.
2） 人称代词宾格的用法
① 作及物动词的宾语 e.g. Tell him\her to call back a little later.
② 作介词宾语 e.g. This pen is bad. I can’t write with it.
③ 作表语 人称代词作表语时，通常要用宾格
e.g. —Who is knocking at the door? —It’s me.
