Is the expression: "You are the ones that do not understand", correct or should I say: "You are those who do not understand"?
What exactly are you trying to convey with this? In a situation where, for example, there are several people telling you that you don't understand something, you might well respond "You are the ones who don't understand". Is this what you are intending? "You are those who do not understand" is incorrect.
You have answered my question. Thank you very much!