YOU SAID:
It must be my birthday
INTO JAPANESE
それは私の誕生日をする必要があります。
BACK INTO ENGLISH
You need to do it for my birthday.
INTO JAPANESE
私の誕生日のために行う必要があります。
BACK INTO ENGLISH
You need to do for my birthday.
INTO JAPANESE
私の誕生日に行う必要があります。
BACK INTO ENGLISH
You must do for my birthday.
INTO JAPANESE
私の誕生日に行う必要があります。
BACK INTO ENGLISH
You must do for my birthday.
That didn't even make that much sense in English.