A: She refused?
B: Yes. Do you think I can persuade her if I try again?
A: She’s not the kind of woman you can persuade.
B: I know her characteristic, but I don’t give up the chance.
A: You know, you are flogging a dead horse. Up till now, no have ever seen successful in talking her to anything she refused.
flog a dead horse
Flog a dead horse的字面意思是“打死一匹死馬”，比喻為“徒勞，白費力氣”或者是“事情已經決定，不必再加討論”的意思。其英文解釋為：to insist on talking about something that no one is interested in, or that has already been thoroughly discussed。
e.g. The history teacher lectured us every day about the importance of studying history, until we begged him to stop flogging a dead horse.
Jill: I think I'll write the company president another letter asking him to prohibit smoking.
Jane: There's no use beating a dead horse, Jill; he's already decided to let people smoke.
1. give up：停止，放棄
e.g. He was compelled by illness to give up his studies.
e.g. Father told Harris not to give up his friends when he moved away.
2. up till now：直到現在
e.g. Up till now, The shadow over me still fails to recede.
e.g. Problems of ours are that up till now we have not found an exact method to solve this difficulty yet.
3. be successful in sth.：在……取得成功
e.g. Why do you feel you will be successful in this work?
e.g. He was successful in the examination.
4. talk sb. to sth. ：說服某人做某事
e.g. All levels of the oil industry are prone to talk themselves into a crisis.
e.g. Don't you ever try to talk me into consent on his behalf.