YOU SAID:
i dont know what is this
INTO JAPANESE
私はこれは何を知らない
BACK INTO ENGLISH
I do not know what this is
INTO JAPANESE
私はこれが何かわからない
BACK INTO ENGLISH
I don't know what this is
INTO JAPANESE
私はこれが何か知らない
BACK INTO ENGLISH
I don't know what this is
That didn't even make that much sense in English.