You didn't need to give me any more money you know, but thank you.

你知道你本不需要再给我钱了，不过谢谢了。

《柯林斯英汉双解大词典》

It's likely that the effect of a thank you on prosocial behavior is more powerful on people we don't know, because strangers are more cautious about helping each other in the first place.

表示感谢的行为可能对陌生人的亲社会行为影响更大，因为人们首次帮助陌生人时会更谨慎。

youdao

Thank you for your information. Before I make a decision I should know more about your corporation. Could I have your price list of the matt tiles?

谢谢您提供的这些信息，我要对贵公司进一步了解之后，才能做决定。您能给我一份哑光砖的价目表吗？

youdao