For example, ancient Egyptian. I know we were able to learn to read the language after the discovery of the Rosetta Stone, but how do we know the pronunciation? When watching history shows, or even movies, Egyptian has a distinct sound. How do we know words like "Tutankhamun" are pronounced the way they are?
u/Osarnachthis provided an excellent answer to this in How do we know what Ancient Egyptian (or any ancient language) sounded like? How accurate are names like “Osiris” and “Tutankhamen” to what they actually sounded like when spoken by Ancient Egyptians?