YOU SAID:
I don't understand what you say to me
INTO JAPANESE
あなたが私に何を言っているのか理解できません
BACK INTO ENGLISH
I don't understand what you're saying to me.
INTO JAPANESE
私はあなたの言っていることがわからない。
BACK INTO ENGLISH
I do not understand you.
INTO JAPANESE
私はあなたの言っていることがわからない。
BACK INTO ENGLISH
I do not understand you.
That didn't even make that much sense in English.