不定代词大都可代替名词和形容词，在句中可用作主语、宾语、表语和定语。如：

1.用作主语

Both of them are waiters.他们俩人都是男侍者。

Is everybody here?人都到了吗?

2.用作宾语

I know little about the novel关于这本小说我知道的很少。

I am speaking for myself，not for others.我只代表自己，不代表别人发言。

I was interested in everything that the old man told me.我对于这位老人告诉我的一切都感兴趣。

3.用作表语

That's all for today. class is dismissed.今天就讲这一些。现在下课。

This book is too much for me.这本书对我说太难了。

4.用作定语

Study well and make progress every day.好好学习，天天向上。

He has some English books.他有一些英文书。

china will become a powerful modern country in another twenty years.再过二十年中国将成为现代化强国。

[注]有些不定代词也可用作同位语和状语。如：

Wang and Li both made good progress.王和李两人都有很大进步。

They all went to the Zoo.他们都去动物园了。

Are you any good at mathematics?你数学好吗?

The meeting lasted some two hours.会议进行了两个小时左右。