Formal:
* خیلی ممنون (Kheyli mamnoon): This is the most common and polite way to express gratitude. It literally translates to "very thankful."
* خیلی سپاسگزارم (Kheyli sepasgozaram): This is a more formal and respectful way to say "thank you very much." It translates to "I am very grateful."
Informal:
* خیلی ممنونم (Kheyli mamnoonam): This is a slightly more informal version of "خیلی ممنون," but still polite.
* خیلی ممنون از شما (Kheyli mamnoon az shoma): This is a more personal way to say "thank you very much," adding "from you" at the end.
* تشکر (Tashakor): This means "thank you" and can be used on its own, or with "خیلی" (kheyli) for emphasis.
You can also combine these phrases with other expressions:
* خیلی لطف کردید (Kheyli lotf kardid): "You were very kind"
* خیلی زحمت کشیدید (Kheyli zahmat keshidid): "You worked very hard"
Remember, the best choice will depend on the specific situation and your relationship with the person you are speaking to.