[1] The Khorasani dialect was spoken by the native and original people of this historical territory, which encompassed the modern-day countries of Tajikistan, Afghanistan, Uzbekistan, Turkmenistan and all the northeastern parts of Iran.
It is spoken in the east from Herat, from the west to the border of Mazandaran (Shahroud, Damghan), and from the north in Bojnourd.
However, as we move towards the north of Khorasan, the presence of Kurdish and Turkic languages of Khorasan and the effects of these two languages on the Persian dialect of the region increases.
From the south of Khorasan to the nearby city of Nehbandan, the dialects of Sistan and Kerman become more apparent.
[3] However, unlike Ivanov, Kolbasi places the dialects of Khorasan region under a distinct branch of the modern south western Iranian languages, with varieties including Sabzevari, Neyshaburi, Kashmari, Kakhki, Qaeni and Birjandi among the dialects, while considering Mashadi as a standard dialect of standard Iranian Persian.