* obrigado/a - thank you, informal
* muito obrigado/a - thank you very much
* obrigadinho/a - kindly thank you, friendly, you should smile when using this form, or be misinterpreted as being ironic/angry: thanks for nothing/thanks, but no thanks
* muitíssimo obrigado/a - thank you very, very much, I owe you, somewhat formal
* obrigadíssimo/a - thank you very, very much, I owe you, somewhat formal
* agradecido/a(s) - thank you, formal
* muito agradecido/a(s) - thank you very much, formal
* muitíssimo agradecido/a(s) - thank you very, very much, I owe you, formal
* agradecidíssimo/a(s) - thank you very, very much, I owe you, formal
* agradeço-te - thank you deeply, to a friend/coworker/colleague, formal
* agradeço-lhe - thank you deeply, to a superior/stranger, formal
* agradeço-vos - thank you deeply, to 2 or more people, formal
* grato/a(s) - thank you, very formal
* muito grato/a(s) - thank you very much, very formal
* muitíssimo grato/a(s) - thank you very, very much, I owe you, very formal
* gratíssimo/a(s) - thank you very, very much, I owe you, very formal
