题目内容：

When I was studying here ,I wanted to turn teacher in the future.这句话对吗?
那这两句呢：When I was studying here ,I wanted to be a teacher in the future.
When I was studying here ,I wanted to become a teacher in the future
如果都可以的话,其中的turn,be,become是什么动词?
既然是系动词的话，系动词不是连接主语和表语么，那主语是I，谓语应该是want呀？turn怎么会是系动词呢