YOU SAID:
A very merry un-birthday to you
INTO JAPANESE
あなたにとてもメリーな誕生日はありません
BACK INTO ENGLISH
You do not have a very Merry birthday
INTO JAPANESE
あなたはとてもメリーの誕生日がありません
BACK INTO ENGLISH
You do not have a very Merry birthday
That didn't even make that much sense in English.