Bangru — more commonly called Haryanvi, and Deswali by its own speakers in the core — is a Western Hindi variety in the same group as the Kauravi that standard Hindi was standardised from. That closeness is the problem: because it is audibly Hindi-adjacent, its speakers are counted as Hindi speakers, it has no literary standard, and the prestige it lacks in offices it makes up for on stage, where saang and ragini are performed in nothing else. The region's real interest is that four related but distinguishable varieties meet inside it, and the transitions are geographic rather than administrative — Bangru gives way to Bagri as the sand starts, to Ahirwati and Mewati as the Aravalli spurs rise, and to Kauravi across the Yamuna.
Bangru (Haryanvi, Deswali)Indo-Aryan, Western Hindi
The Rohtak–Jind–Sonipat–Hisar core. Marked by the -s future, the retention of an open final vowel where standard Hindi has none, and a very high rate of vowel nasalisation.
Speakers: About 98 lakh returned as Haryanvi in the 2011 Census, under Hindi
BagriIndo-Aryan, Rajasthani group
Sirsa, Fatehabad and western Hisar, continuing into Rajasthan and southern Punjab. Grammatically it leans Rajasthani rather than Western Hindi, which is why the sand boundary is also a language-family boundary.
AhirwatiIndo-Aryan, Rajasthani group
Rewari, Mahendragarh and the Narnaul tract, transitional towards Mewati and Shekhawati and spoken largely by Ahir cultivating communities.
MewatiIndo-Aryan, Rajasthani group
Nuh, Firozpur Jhirka, Tijara and Alwar. It carries a large Perso-Arabic vocabulary from the Meo community's Muslim practice sitting on top of a Rajasthani grammar, and it holds the Pandun ka Kada epic.
PuadhiIndo-Aryan, transitional Punjabi–Western Hindi
Ambala, Panchkula and the Shivalik edge. It shades into Malwai Punjabi to the north-west and is the point at which the region's speech stops sounding Haryanvi.