英语 没有听懂对方说什么 怎么说

I’m sorry, I didn’t catch what you said. Could you repeat it? 不好意思，我没听到你说了啥，能重复一遍吗？

sorry, This question is too difficult for me to answer.

i am Sorry,  I forgot the details

没听懂老外说了啥？你可别说“Pardon”啊！不然你永远不懂！