3. 名词性物主代词的作用相当于名词,在句中可用作主语、宾语和表语。
Our school is here, and
theirs is there.我们的学校在这儿,他们的在那儿。(作主语)
--- Is this English-book yours?
这是你的英语书吗?(作表语)
--- No. Mine is in my bag.不是,我的在书包里。
I've already finished my homework.
Have you finished yours? 我已经做完家庭作业。你做完了吗? (作宾语)