YOU SAID:
He says no one has to know what we do,
INTO JAPANESE
彼は私たちが何をしているのか誰も知る必要がないと言います、
BACK INTO ENGLISH
He says no one needs to know what we are doing,
INTO JAPANESE
彼は私たちが何をしているのか知る必要はないと言っています、
BACK INTO ENGLISH
He says he does not need to know what we are doing,
INTO JAPANESE
彼は私たちがしていることを知る必要はないと言っています、
BACK INTO ENGLISH
He says he does not need to know what we are doing,
That didn't even make that much sense in English.