whose: pron. 谁的（疑问代词）
Whose bag is this?
这个包是谁的
Whose shoes are those?
那是谁的鞋
Whose book is this?
这是谁的书
Whose car is this?
这是谁的汽车
It doesn't matter whose fault it was. Let's focus on fixing the problem.
谁的错不重要。咱们好好想想怎么解决问题。
Whose turn is it?
轮到谁了
