Originally Posted By: LukeJavan8


And I believe the everyday spoken Greek was/is called Koine

Sort of. Mostly only after about the first century BC. And that's probably not what the speakers back then would have called it, any more than earlier eras thought of themselves as speaking "classical" language, or people at Shakespeare's time thought they were using "Elizabethan" English. It's a later designation in order to distinguish it from Classical or Byzantine or Modern Greek.