Vajjika or Bajjika is the old and mother tongue language of Muzaffarpur.
Here we have a clip from one of the literature book.
Bajjika is spoken in Vaishali, Muzaffarpur, Samastipur, Sitamarhi, Eastern part of Saran, Sheohar and some other districts. It is also spoken in a part of the Darbhanga district adjoining Muzaffarpur and Samastipur districts.
