1、含有-one和-body的不定代词功能和意义基本相同，含有-one的不定代词比含有-body的不定代词正式。

2、所有不定代词都当作单数对待。

Someone is asking to see you. / Nobody is absent.

3、带有some的复合不定代词一般用于肯定句，带有any的复合不定代词一般用于否定句和疑问句。

Someone suggests putting off the meeting.

Did you meet anyone on your way home.

★含有some的复合不定代词也可以用于疑问句中，表示肯定的的意思。含有any的复合不定代词也可以用于肯定句中表示“任何人”或“任何事”。

Why don't you say something? Anybody can go.

4、somebody和nobody可以表示“重要人物”和“小人物”的意思。

He thinks himself a somebody, but he is nobody.

5、else和形容词作复合不定代词的定语时都要后置。

He wanted to read something interesting.

He wants to see nobody else.

（来源：网络）