“……….the nucleus of the Macedonian vocabulary consists of words which have exact correspondence in Greek.The importance of these words and the archaic phonological character of Macedonian lead to the conclusion that these are not borrowings but inherited words: this fact is confirmed by the genetic unity of Macedonian and Greek.
Moreover, the numerous lexical and phonological isoglosses in Macedonian and the different Greek dialects confirm the supposition of genetic unity.” 

Vladimir I. Georgiev, “Introduction to the History of the Indo-European Languages”, Sofia 1981, p. 169