That all depends on what you're trying to say in Greek. Your best bet would be to find a translator, either online or a book, and go from there.
They were the first people to write the alphabet. The Ancient Greek's
slate
noo noo sticks
Ashley-ΑΣΗΛΕΨ
Apherdite i think ?
An oracle
Polyphemus would look like this in Greek: Πολύφημος
ΣΕΝΝΙΦΕΡ Please note, however, that there is no "J" in the ancient greek alphabet, so it was replaced with the letter it would have been in ancient greek; "Sigma" or "S".
The Ancient Greek poet Homer.
ΞΟΛΒΨ Hope this helps!
Παρθενών [Parthenon] (Ancient Greek) , Παρθενώνας [Parthenonas] (Modern Greek)
ΠΡΙΝΞΕΣΣ Hope this helps!