YOU SAID:
I can't believe that the cat is dead.
INTO JAPANESE
私は猫が死んだとは信じられない。
BACK INTO ENGLISH
I can not believe that the cat is dead.
INTO JAPANESE
私は猫が死んだとは信じられない。
BACK INTO ENGLISH
I can not believe that the cat is dead.
That didn't even make that much sense in English.