在英语中，请求别人签名可以有多种表达方式，以下是一些常用的句子：

Can I have your signature？

Could you sign your name for me？

I would like to have your signature.

Can I please have your autograph？

Could you help me to sign autographs？

Can you give you your sign？

Could you please sign for me？

May I have your signature here？

Please sign here.

Can you sign here, please？

这些句子都可以礼貌地请求别人在你的文件或物品上签名。根据具体的场合和对象，你可以选择合适的句子来表达你的请求。