Formal:
* धन्यवाद (Dhanyavaad): This is the most common and formal way to say "thank you".
* आपका धन्यवाद (Aapka Dhanyavaad): This is a more polite way to say "thank you" and literally means "Your thanks".
Informal:
* शुक्रिया (Shukriya): This is a more casual and friendly way to say "thanks".
* बहुत धन्यवाद (Bahut Dhanyavaad): This is a more emphatic way to say "thank you" and means "Many thanks".
Other options:
* कृतज्ञता (Kritagnata): This is a more formal way to express gratitude and means "gratitude".
* आभारी हूँ (Aabhari Hoon): This is a way to say "I am grateful" and is more formal than "Shukriya" but less formal than "Dhanyavaad".
The best way to choose which phrase to use depends on the situation and the person you are talking to. For example, you would use "Dhanyavaad" when speaking to a teacher or an elder, but you could use "Shukriya" when speaking to a friend.