Thank you (fa'afetai); farewell (tofa).
As there is no direct word for Grandpa in the Samoan language, Tama (Father) is always used, so I would say: Fa'afetai, Tama.
Samoan Pride
If you're saying it in reply to someone who's asked 'how you are', then you say "Manuia fa'afetai".
Michelle is not a Samoan name so would have no translation for it in the Samoan language.
Michelle is not a Samoan name so would have no translation for it in the Samoan language.
Jessica is not a Samoan name so there's no translation for it in the Samoan language.
Fa'afetai, maoa'e sivasivaga
Fa'afetai mo mea uma
peace senor
Se'evae
Brady = buleiti
Tofa soifua, Tofaina, Soifua, Tofa (all these words are the respectful ways of saying farewell/goodbye. Bye is Fa, which is the an abbreviation for Tofa.