YOU SAID:

I don't know Family has said nothing more about cows.

INTO JAPANESE

私は家族が牛についてこれ以上何も言わなかったことを知らない。

BACK INTO ENGLISH

I don't know that the family said nothing more about the cow.

INTO JAPANESE

家族が牛についてこれ以上何も言わなかったことは知りません。

BACK INTO ENGLISH

I don't know that the family didn't say anything about the cow.

INTO JAPANESE

家族が牛について何も言わなかったことは知らない。

BACK INTO ENGLISH

I don't know that my family didn't say anything about cows.

INTO JAPANESE

私の家族が牛について何も言わなかったことは知りません。

BACK INTO ENGLISH

I don't know that my family didn't say anything about cows.