@Zaniel,
Salve and
vale are the Latin terms generally used for greeting and
farewell. "Yes and "no" are a bit more difficult. There are are no words
that exactly correspond. For an affirmative answer, you might use
ita
(thus, so),
vero (truly) or
certe (certainly). For a negative answer,
non
est (it is not so),
minime (not at all) or
nullo modo (by no means).