anyone是代词，不是名词，不分单复数的。释义：(用于否定句、疑问句，也用于if或whether之后，或紧接prevent、forbid、avoid等动词，代替someone)任何人；随便哪个人；重要人物。
I would prefer it if you didn't tell anyone.
我希望你别告诉任何人。
I don't want anyone getting the wrong idea.
我不希望任何人有所误会。
Keep down!You mustn't let anyone see you.
蹲下！一定不要让人看见你。
It was the best possible surprise anyone could have given me.
那是我曾感受过的最大惊喜。
1、anyone指“任何人”，不指“任何一个”，any one指“任何一个”，但是有时也指“任何人”，现在比较不普遍那样说；
2、anyone不能同one或one's同时使用，如Ifanyonecomes,ask him to wait里面的him不可替换成one；
