Translation guide
In Japanese, 'birthday' is most commonly expressed as 誕生日 (たんじょうび). However, natural usage often involves set phrases for congratulations, asking about dates, or stating one's age. This guide covers the core noun, common expressions, and cultural notes.
When is your birthday?
Referring to the anniversary of the day someone was born, as a noun.
Expressing 'happy birthday' or giving birthday wishes.
Polite and standard way to say 'Happy birthday'. Use with acquaintances, colleagues, or in formal settings.
Inquiring about the date of someone's birthday.
Standard way to ask 'When is your birthday?'. Can be made more polite by adding お before 誕生日.
Saying how old one is turning or has turned.
Used to say 'I will turn X years old'. The verb なる indicates a change of state. Often used when a birthday is approaching or has just passed.
Referring to a birthday party or event.
Adding お before 誕生日 (お誕生日) makes the word more polite. It is common when referring to someone else's birthday, especially in formal situations or when showing respect.
When is your birthday? (polite)
誕生日 (たんじょうび) means 'birthday' (the anniversary). 生年月日 (せいねんがっぴ) means 'date of birth' (year, month, day) and is used on official documents. Do not confuse them.
I forgot her birthday.
His birthday is next month.
バースデーケーキを買った。
I bought a birthday cake.
Happy birthday, teacher.
Casual 'Happy birthday'. Use with friends, family, or people of equal/lower status.
Happy birthday, Mom!
Direct loan from English. Used mainly in songs or very casual, playful contexts. Not a standard greeting.
We all sang 'Happy Birthday'.
When is your birthday? (polite)
When's your birthday? (casual)
Literally 'What month, what day were you born?'. More specific than asking 'when', and common when filling out forms or getting to know someone.
Excuse me, what is your date of birth?
I'll be 20 next month.
I turned 25 yesterday.
Simple statement of current age. Not specifically tied to birthday, but can be used in context.
I'm 18 today.
Standard term for a birthday party. Often used for children's parties or casual gatherings.
We're having a birthday party for my daughter on Sunday.
Also common, using the loanword パーティー. Slightly more modern/casual feel.
I went to a friend's birthday party.
生年月日を記入してください。
Please fill in your date of birth.
We celebrated his 60th birthday.
還暦 (かんれき) is the celebration of one's 60th birthday in the traditional Japanese calendar.