YOU SAID:

one plus one is two that i don't know.

INTO JAPANESE

1プラス1は私が知らない2です。

BACK INTO ENGLISH

1 plus 1 is 2. I do not know.

INTO JAPANESE

1プラス1は、私にはわからない2です。

BACK INTO ENGLISH

1 plus 1 is 2, I do not know.

INTO JAPANESE

1プラス1が2である、私は知りません。

BACK INTO ENGLISH

1 plus 1 is 2, I do not know.