1.(用于疑问句或if从句时)谁,任何人

If anyone calls, tell him I'll be back about three o'clock.

如果有人来电话,就说我三点左右回来。

2.(用于否定句时)任何人

There wasn't anyone there.

那儿一个人也没有。

3.(用于肯定句时)无论谁,无论哪个人

Anyone who has worked here for over three years is eligible for sick pay.

凡在这儿工作了三年以上的人都有资格获得病假工资。

而everyone 代词 pron.

1.每人,人人

Everyone wants to attend the concert