The pronunciation of Ancient Greek varied much according to time and place, and differed in many important respects from that of the modern language. While in general Greek of the classical period was a phonetic language, i.e. its letters represented the sounds, and no heard sound was unexpressed in writing (but see cross108), in course of time many words were retained in their old form though their pronunciation had changed. The tendency of the language was thus to become more and more unphonetic. Our current pronunciation of Ancient Greek is only in part even approximately correct for the period from the death of Pericles ( cross429 B.C.) to that of Demosthenes ( cross322); and in the case of several sounds, e.g. ζ, φ, χ, θ, it is certainly erroneous for that period. But ignorance of the exact pronunciation, as well as long-established usage, must render any reform pedantical, if not impossible. In addition to, and in further qualification of, the list of sound equivalents in 1 we may note the following:
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].