in questions, used to emphasize the question word

(用于疑问句中强调疑问词)究竟，到底

How ever did he manage that?

他到底是怎么应付过去的?

What ever have you done to him?

你究竟对他做了什么?

Why ever would anyone/Why would anyone ever want to hurt her?

有人要去伤害她究竟是为什么?