我听不懂你说的话英文是什么

I can't catch you 口语

I can't understand what you say 较正式

带有不耐烦的口吻：I don't know what you say.

I can't follow you.

I don't know what you are talking about!

I don't understand what are you talking about!
I couldn't understand what are you talking about!

I don't know/understand what you are talking about.
I don't understand/know what you are saying.