The Japanese word for “birthday” is 誕生日 (tanjōbi, birthday). To wish someone a happy birthday, add the expression for congratulations: 誕生日おめでとう (tanjōbi omedetō, happy birthday).
That is the basic answer, but the best wording depends on your relationship with the person. Japanese has casual, polite, and warmer variations, so learning the whole expression is more useful than memorizing the noun alone.
The Direct Answer and Its Meaning
誕生日 (tanjōbi, birthday) is a noun. It combines 誕生 (tanjō, birth) with 日 (bi, day in this compound), so its literal structure is “birth day.”
Some kanji dictionaries give the final character the meanings “day; sun,” sometimes compressed to “day sun.” In this word, it means “day,” not “sun.” A translation that says the noun “means birthday” is correct.
To say birthday as a greeting, you need more than the noun. 誕生日おめでとう (tanjōbi omedetō, happy birthday) literally combines “birthday” with “congratulations,” but its natural English translation is “Happy birthday.”
If you arrived through a search such as “say birthday' Japanese,” “birthday' Japanese,” or “tanjoubi',” the apostrophe is simply search noise. It is not part of the Japanese word or its romanization.
Pronounce 誕生日 (tanjōbi, birthday) in five even mora beats: ta-n-jo-o-bi. The macron in “jō” represents a long vowel, so do not shorten it. Clear mora timing matters more than trying to copy an isolated pitch pattern perfectly.
Formal, Informal, and Friendly Expressions
Choosing between formal and informal language is mainly about your relationship with the recipient. The safest informal ways suit friends and family, while polite wording is better for someone you address respectfully.
Expression: Japanese script + Hepburn + English meaning | Best use |
|---|---|
誕生日 — tanjōbi — birthday | The neutral noun |
お誕生日 — o-tanjōbi — birthday with a polite prefix | Respectful reference to someone’s birthday |
誕生日おめでとう — tanjōbi omedetō — happy birthday | Friends, relatives, and people close to you |
お誕生日おめでとうございます — o-tanjōbi omedetō gozaimasu — happy birthday in polite language | Respectful or more formal situations |
おめでとう — omedetō — congratulations | A short casual greeting when the occasion is obvious |
おめでとうございます — omedetō gozaimasu — congratulations in polite language | A polite congratulatory expression |
ありがとう — arigatō — thank you | A casual response to a birthday wish |
ありがとうございます — arigatō gozaimasu — thank you in polite language | A polite response to a birthday wish |
Online, お誕生日おめでとう (o-tanjōbi omedetō, happy birthday) is often typed “otanjoubi omedetou.” The casual 誕生日おめでとう (tanjōbi omedetō, happy birthday) similarly appears as “tanjoubi omedetou.”
You may also see “arigatou” for ありがとう (arigatō, thank you) and “omedetou” for おめでとう (omedetō, congratulations). These spellings show long vowels with “ou.” Standard Hepburn commonly uses macrons, making the pronunciation clearer.
Four Birthday Sentences in Context
Use a complete sentence when you want to mention a birthday rather than offer a wish:
今日は私の誕生日です。
Kyō wa watashi no tanjōbi desu.
Today is my birthday.
For a friend or close family member, this is direct and natural:
誕生日おめでとう！
Tanjōbi omedetō!
Happy birthday!
For a person you address politely, use this version:
お誕生日おめでとうございます。
O-tanjōbi omedetō gozaimasu.
Happy birthday.
You can follow the greeting with a warm wish for the coming year:
すてきな一年になりますように。
Suteki na ichinen ni narimasu yō ni.
I hope you have a wonderful year.
A birthday message does not need to be long. A greeting plus one sincere sentence about the person’s coming year is often enough to sound warm without becoming difficult to produce.
Common Mistakes
Using the noun as the entire greeting. Learners sometimes say only 誕生日 (tanjōbi, birthday). That names the occasion but does not express congratulations. Add おめでとう (omedetō, congratulations) when you want to make a birthday wish.
Assuming one expression fits everyone. A casual message can sound too familiar in a formal relationship. Conversely, highly polite language may feel distant between close friends. Match the formal or informal level to how you normally address that person.
Shortening long vowels. Both 誕生日 (tanjōbi, birthday) and おめでとう (omedetō, congratulations) contain long vowels. Keep a steady rhythm and allow the long vowel to occupy two mora beats.
Treating pitch accent as one fixed melody. Regional variations exist, and sentence-final intonation can also change the warmth or emphasis of a wish. Focus first on mora timing, vowel length, and clarity across the full phrase.
Adding anime-style words for “you.” teachers have encountered learners using second-person terms taken from anime in ordinary conversation. In a real birthday message, the person’s name—or no pronoun at all—usually sounds more natural.
Practise a Message You Can Actually Use
Build your message around one real person. Decide whether your relationship calls for casual or polite language, choose one birthday expression, and add a short wish that you can pronounce comfortably.
A standard 25-minute Kind Japanese one-on-one lesson over LINE can follow a focused flow: a brief warm-up, a target speaking task, correction, and a learner-owned review note or question list. For birthday practice, you might rehearse the greeting, explain whose birthday it is, and repeat the corrected version aloud.
A useful review note records:
- What you tried to say
- The corrected sentence
- One question that makes you repeat the same pattern
- One pronunciation point, such as vowel length or sentence-final intonation
For a broader study system, read How to Learn Japanese Fast Without Wasting Time. If you are deciding how live guidance fits alongside self-study, Is It Worth Paying for Japanese Lessons? offers a practical comparison.
When you want personal feedback on your birthday message and pronunciation, book a Free Trial Lesson with Kind Japanese.
FAQ
What is the difference between the plain and polite nouns?
誕生日 (tanjōbi, birthday) is the neutral noun, while お誕生日 (o-tanjōbi, birthday with a polite prefix) sounds more courteous. Use the polite form when addressing someone respectfully, but remember that the relationship and the full sentence matter more than adding the prefix mechanically in every single birthday message.
Can I use only the congratulatory word?
You can use おめでとう (omedetō, congratulations) by itself when the birthday context is already obvious, especially with someone close. For a clearer wish, include 誕生日 (tanjōbi, birthday), and add ございます (gozaimasu, polite ending) when greater politeness suits your relationship with the person or the social setting at hand.
Is the common romanization with “ou” wrong?
Spellings such as “tanjoubi omedetou” and “otanjoubi omedetou” are common ways to type long vowels without macrons, so readers generally understand them. Standard Hepburn in learning materials uses macrons—tanjōbi, omedetō, and o-tanjōbi—which make vowel length visible and support more accurate pronunciation in speech.
How can I practise a birthday message before sending it?
Draft one short message, read it aloud, and check whether its level of politeness matches the recipient. In a one-on-one lesson, a teacher can help you rehearse the full phrase, hear vowel length and intonation, and create one corrected version that you can confidently practise again.
