1、含有-one和-body的不定代詞功能和意義基本相同，含有-one的不定代詞比含有-body的不定代詞正式。

2、所有不定代詞都當作單數對待。

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

3、帶有some的復合不定代詞一般用于肯定句，帶有any的復合不定代詞一般用于否定句和疑問句。

Someone suggests putting off the meeting.

Did you meet anyone on your way home.

★含有some的復合不定代詞也可以用于疑問句中，表示肯定的的意思。含有any的復合不定代詞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和形容詞作復合不定代詞的定語時都要后置。

He wanted to read something interesting.

He wants to see nobody else.

（來源：網絡）