Thanks:
* நன்றி (nanRi): This is the most common and straightforward way to say thank you.
* நன்றி சொல்ல வார்த்தைகள் இல்லை (nanRi solla vaarththaigal illai): This is a more emphatic way of saying thank you, translating to "Words are not enough to express my gratitude."
You're welcome:
* சாரி இல்லை (saari illai): This literally means "there is no problem" and is the most common way to respond to a thank you.
* வணக்கம் (vanakkam): This is a formal way of saying "welcome" and is often used when someone is expressing gratitude for a service or favor.
* நீங்க சொல்றது எல்லாம் சரி (neega solrathu ellam sari): This means "everything you say is right" and can be used to express gratitude for someone's kindness.
Remember: Tamil is a very nuanced language, and the best way to express your gratitude will depend on the context and the relationship you have with the person you're thanking.