History of pronunciation

Just for interest, this link is to a site that describes how the pronunciation of the Greek alphabet has changed over time. This explains why Modern Greek seems to have several letters that have the same phonetic value such as η, ι & υ, all sounding like "ee".

Turns out that some 16th century Monk did a lot of research and came to the conclusion that the original ancient Greek had different pronunciations, hence Η (η) originally sounded more the "ai" in air, Ι (ι), was the "i" from ski, as in modern Greek, and Y (υ) would be more like the "ew" sound from the "u" in tune.

http://www.biblicalgreek.org/links/pronunciation.php