Yes, wishing someone a happy Rosh Hashanah is a thoughtful and kind gesture to celebrate the Jewish New Year. Common greetings you can use include:
- "Shanah Tovah" (שנה טובה) — meaning "Good Year"
- "Shanah Tovah Umetukah" — meaning "A good and sweet year"
It's a way to express good wishes for health, happiness, and renewal in the coming year.