Modern Greek derives from the Koine via the local varieties that presumably arose during the Byzantine period and is the mother tongue of the inhabitants of Greece and of the Greek population of the island of Cyprus. Before the population exchange in 1923, there were Greek-speaking communities in Turkey (Pontus and Cappadocia). Greek is also the language of the Greek communities outside Greece, as in the United States, Canada, and Australia. There are Greek-speaking enclaves in Calabria (southern Italy) and in Ukraine. Two main varieties of the language may be distinguished: the local dialects, which may differ from one another considerably, and the Standard Modern Greek (Greek: Koini Neoelliniki, “Common Modern Greek”).