请求别人做某事时有哪些表示,对方如何肯定否定回答(用英语）用问句表示,肯定否定回答.越多越快越好!

直接说would you do me a favor? 或者 Could you give me a hand? 就可以了，不一定要加please这个词，因为这个词要注意语调，如果一定要说would you please do sth for me? 其中please这个单词一定要读柔和的升调，不知楼主语音语调怎么样，如果语调掌握不好，把please读成重读降调的话（大多数初学者一个单词一个单词说的话都会不小心读成这样）这句话的意思就会变成："你就帮我做一下这件事又能怎么样？你有不会少一根汗毛。"听起来就不那么委婉礼貌了，所以英语里面please这个单词得慎用。
肯定回答sure! 就可以了
否定回答一般都说“I would like to, but......"

Would you please do sth for me?
Could you please do sth for me?
May I ask you a favor ?
肯定回答：Sure!
否定回答：I'm sorry I can't because ....

最简单的表达 can you help me ?
肯定 yes ,my pleasure
否定 I am sorry .....
还有像could you do me a favor?
may i ask you a favor?
would you mind if you can do sth for me?
would you give me a hand?

Can you help me?
Yes,I can./Oh.Sorry ,although I want to help you ,I ....
Could you have a hand with me ?
OK./(同上）

Could you do me a favour?Could you help me?Would you mind if you can do sth for me?Would you give me a hand?May I ask you a favor 肯定回答：Sure !with plesure否定回答 I'm sorry I'm afraid