The official language of the country is Albanian which is spoken by the vast majority of the country's population. Its standard spoken and written form is revised and merged from the two main dialects, Gheg and Tosk, though it is notably based more on the Tosk dialect. The Shkumbin river is the rough dividing line between the two dialects. Also a dialect of Greek that preserves features now lost in standard modern Greek is spoken in areas inhabited by the Greek minority. Other languages spoken by ethnic minorities in Albania include Aromanian, Serbian, Macedonian, Bosnian, Bulgarian, Gorani, and Roma. Macedonian is official in the Pustec Municipality in East Albania. According to the 2011 population census, 2,765,610 or 98.8% of the population declared Albanian as their mother tongue (mother tongue is defined as the first or main language spoken at home during childhood).