YOU SAID:

I didn't eat that cow

INTO JAPANESE

その牛を食べていません。

BACK INTO ENGLISH

Don't eat the cow.

INTO JAPANESE

牛を食べてはいけない。

BACK INTO ENGLISH

Do not eat beef.

INTO JAPANESE

食べてはいけません。

BACK INTO ENGLISH

Do not eat.

INTO JAPANESE

食べてはいけません。

BACK INTO ENGLISH

Do not eat.