It is difficult to monitor the evolution of Koine Greek and its splitting into the modern Greek dialects; certain researchers make the hypothesis that the various local varieties were formed between the 10th and the 12th century (as part of an evolution starting a few centuries before), but it is difficult to draw some safer conclusions because of the absence of texts written in the vernacular language, when this initial dialect differentiation occurred.
Very few paradigms of these local varieties are found in certain texts, which however used mainly learned registers.
Dialect is recorded in areas outside Byzantine control, first in legal and administrative documents, and then in poetry.
The earliest evidence for literary dialects comes from areas under Latin control, notably from Cyprus, Crete, and the Aegean islands.
By that time, however, the form of Demotic used in practice was no longer the pure popular dialect, but had begun to assimilate elements from the Katharevousa tradition again.
In 1982 diacritics were replaced by the monotonic orthography.
His language became influential on the further course of standardisation that led to the emergence of the modern standard form of Demotic, based on the south-western dialects.
Spoken modern vernacular Greek can be divided into various geographical varieties.The first systematic scholarly treatment of the modern Greek dialects took place after the middle of the 19th century, mainly thanks to the work of the prominent Greek linguist Georgios Hadjidakis.Therefore, the dialects' forms are known to us only during their last phase (from the middle of the 19th century, and until the panhellenic dominance of the Standard Modern Greek).During the Cretan Renaissance in the 16th and early 17th centuries there existed a flourishing vernacular literature in the Cretan dialect, based on Italian literary influences.Its best-known specimen today is the verse romance Erotokritos, by Vitsentzos Kornaros (1553–1614).The linguistic varieties of Modern Greek can be classified along two principal dimensions.