The two you need are जन्मदिन मुबारक हो, which is warm and universal, and जन्मदिन की शुभकामनाएँ, which is more formal and suits a message to a senior or a colleague. मुबारक is Arabic in origin but entirely standard in Hindi, used by everyone regardless of religion.

These are said downward in age — by a parent, grandparent, aunt or older colleague. Saying जीते रहो to someone older than you is a genuine misstep, since blessings flow from elder to younger. To an elder you say शुभकामनाएँ instead, or simply touch their feet and let them bless you.

These stack naturally onto a greeting. A complete message might run: जन्मदिन मुबारक हो! आपके सारे सपने पूरे हों। Note the subjunctive verb forms — हो, मिले, पूरे हों — which is the mood Hindi uses for wishes and blessings throughout.

A few practical details. Cake-cutting is near-universal in urban India, and the birthday person feeds the first piece to their parents or closest family rather than eating it themselves. Being fed cake by hand, and having it smeared on your face, is standard among friends.

Many Indian families also mark the birthday according to the Hindu lunar calendar as well as the Gregorian date, meaning some people genuinely have two birthdays a year. A visit to a temple in the morning and sweets distributed to colleagues are both common.

Touching the feet of parents and elders on your birthday to receive their आशीर्वाद remains widespread, including among young urban people who would not do it on an ordinary day.

One small warning about wishing people early. Many Indian families consider it inauspicious to give birthday wishes before the day itself, so the midnight message — sent at exactly twelve o’clock by friends, and increasingly by everyone — exists partly to solve that problem. Wishing someone a day in advance because it is convenient for you is likely to be gently corrected, and among older relatives it can genuinely bother people.

जन्मदिन has a न्म cluster in the middle where n and m run together — four beats total. मुबारक is four even beats with no stress. शुभकामनाएँ is long and nasalised at the end; break it as shubh-kaam-naa-yen. तरक़्क़ी doubles the deep क़, usually simplified to a plain k. And दुआ is two clean light syllables.

• Saying जीते रहो or ख़ुश रहो to someone older than you. Blessings flow downward only.
• Using मुबारक only for Muslim occasions. It is standard Hindi for any celebration.
• Missing the subjunctive in wishes — it is हो and मिले, not है and मिलता है.
• Eating your own cake first rather than feeding a parent.
• Assuming a Gregorian date is the only birthday being observed.

1. Write a birthday message for a friend and one for a senior colleague.
2. Practise three blessings and note who each is appropriate for.
3. Combine a greeting with two wish clauses into one message.
4. Say जन्मदिन and शुभकामनाएँ slowly until the clusters are clean.
5. Send a real birthday wish in Hindi to someone this month.