1. (表示身份不确定)无论是谁
    You use whoever to refer to someone when their identity is not yet known.

whoever的翻译

    e.g. Whoever did this will sooner or later be caught and will be punished...
           不管是谁干的这事，早晚要被抓住并受到惩罚。
    e.g. Whoever wins the election is going to have a tough job getting the economy back on its feet...
           不管是谁赢得了大选，都将面临恢复经济的严峻任务。

2. (指与人的身份无关)无论是谁
    You use whoever to indicate that the actual identity of the person who does something will not affect a situation.

    e.g. You can have whoever you like to visit you...
           你想要谁来拜访你都可以。
    e.g. Everybody who goes into this region, whoever they are, is at risk of being taken hostage.
           进入这个地区的人，不管是谁，都有被劫为人质的危险。

3. (用在疑问句中代替who作为强调，通常表示惊讶)究竟是谁
    You use whoever in questions as an emphatic way of saying 'who', usually when you are surprised about something.

    e.g. Whoever thought up that joke?...
           到底是谁想出的这个笑话？
    e.g. Ridiculous! Whoever suggested such a thing?
           荒唐！究竟是谁提出了这样的建议？

4. (表示不确定)或是别的什么人（或组织）
    You say or whoever to refer vaguely to another person or organization, especially when you are not sure if you have mentioned the right person or organization.

    e.g. We're not just some big business like Mobil or IBM or whoever...
           我们并不仅仅是某个像美孚、IBM或别的什么公司一样的大公司。
    e.g. The police, or whoever, would not think of looking for him here.
           无论是警方还是其他什么人都不会想到来这里找他。