疑问代词有who(谁，主格)，whom(谁，宾格)，whose(谁的，所有格)，what(什么)和which(哪个，哪些)等。

疑问代词用于特殊疑问句中

疑问代词一般都放在句首，并在句中作为某一句子成分。如：

Who is going to speak to us tomorrow?明天谁来跟我们讲话?(who作主语)

Who told you so?是谁告诉你的?(who作主语)

Whom are you talking about ?你们在说谁?(whom作宾语，但在句首时口语常用who代替whom)

Whose umbrella is this ?这是谁的伞?(whose作定语)

What is that? 那是什么?(what作表语)

What did he say?他说什么?(what作宾语)

Which is yours，the blue pen or the redone?蓝笔和红笔哪一支是你的?(which作主语)

[注一]疑问代词who，what，which等后面加单词ever，可强调语气，表达说话人的各种感情。如：

What ever do you want?你到底想要什么?

Who ever is she looking for ?她究竟是在找谁?

[注二]which表示在一定范围之内的选择，what则没有这种限制。如：

What do you usually have for lunch?你们午饭通常吃些什么?

Which do you like best?你最喜欢哪一个?

Which of you comrades come from the Northeast? 你们同志们中间谁是东北人?

疑问代词可以引导一个间接疑问句

间接疑问句在句中可用作主语、宾语、表语等。疑问代词本身在间接疑问句中又担任一定的句子成分。如：

Who will be in charge of the work is still not decided.谁将负责这项工作，现在还没有决定。(疑问代词who引导一个主语从句，它本身又在从句中用作主语。)

Do you know what his name is?你知道他叫什么名字吗?(疑问代词what引导一个宾语从句，而它本身又在从句中用作表语。)

[注一] what所引导的名词性从句(即主语从句、宾语从句、表语从句) 有时不是间接疑问句。如：

What he says is quite true.他所讲的话很对。(what相当于that which。它引导一个主语从句，这个从句不是间接疑问句。)

Children do what the nurse tells them to do.保育员让孩子干什么他们就做什么。(what引导一个宾语从句，这个从句也不是间接疑问句。)

[注二] whatever，whoever，whichever等词可引导名词性从句。这些名词性从句也不是间接疑问句。whatever，whoever，whichever也可引导表示让步的状语从句。如：

They eat whatever they can find.他们找到什么就吃什么。(whatever引导一个宾语从句，并在从句中作宾语。)

I've got plenty of books 1eft.Whoever wants an extra copy can get one from me.我还剩下许多书，谁还想再要一本可来拿。(whoever引导一个主语从句，并在从句中作主语。)