The main characteristics of Magadhi Prakrit is to mutate 'r' into 's', the 'n' for n, of 'j' for 'y', of 'b' for 'y' In the edicts of Ashoka the change of 'r' to 'h' is established.
The secular use of language came mainly from the east as will be evident from the Prakritpainglam, a comprehensive work on Prakrit and Apabhramsa-Avahatta poetry.
Vachaspati II in his Tattvachintamani and Vidyapati in his Danavakyavali have profusely used typical Maithili words of daily use.
The earliest recorded epigraphic evidence of the script is found in the Mandar Hill Stone inscriptions of Adityasena in the 7th century A.D., now fixed in the Baidyanath temple of Deoghar.
Paul R. Brass wrote that "Grierson judged that Maithili and its dialects could fairly be characterized as the language of the entire population of Janakpur, Siraha, Saptari, Sarlahi, Darbhanga and Madhubani".