YOU SAID:
It is raining cats and dogs, it makes my head hurt
INTO JAPANESE
猫と犬を雨が降っていて、頭が痛い
BACK INTO ENGLISH
Cat and dog are raining and my head hurts
INTO JAPANESE
猫と犬は雨が降っていて頭が痛い
BACK INTO ENGLISH
Cats and dogs are raining and their heads hurt
INTO JAPANESE
猫と犬は雨が降っていて頭が痛い
BACK INTO ENGLISH
Cats and dogs are raining and their heads hurt
That didn't even make that much sense in English.