YOU SAID:
how old do you have to be to drink?
INTO JAPANESE
あなたは何歳で飲まなければならないのですか?
BACK INTO ENGLISH
How old do you have to drink?
INTO JAPANESE
何歳で飲まなければなりませんか。
BACK INTO ENGLISH
How old do I have to drink?
INTO JAPANESE
何歳で飲む必要がありますか?
BACK INTO ENGLISH
How old do I need to drink?
INTO JAPANESE
何歳で飲む必要がありますか?
BACK INTO ENGLISH
How old do I need to drink?
That didn't even make that much sense in English.