KRDS lects

For the lect spoken in Rangpur (Bangladesh), see Rangpuri language. For language of Koch people, see Koch language.

The KRDS lects (or the Kamta, Rajbanshi, Deshi and Surjapuri subgroup) are a cluster of modern lects that are phylogenetic descendants of the proto-Kamta language.^[4] The proto-Kamta language began differentiating after 1250 around Kamatapur, the capital city of Kamata kingdom, as the western branch of the Kamarupi Prakrit,^[5] whereas the eastern branch developed into Early Assamese. Since the 16th century the proto-Kamta community has fragmented giving rise to the differentiated modern lects.^[6] The modern lects are:^[7][8] Kamta (Assam and West Bengal), Rangpuri (Bangladesh), Rajbanshi (Nepal) and Surjapuri (Bihar).^[9]

KRDS lects
KRNB lects, Kamatapuri, Kamta
Native to	India, Bangladesh, Nepal
Region	Northern West Bengal, Western Assam, North Eastern Bihar, Northern Bangladesh, Southeast Nepal
Language family	Indo-European Indo-Iranian Indo-Aryan Eastern Odia–Bengali–Assamese[1] Bengali–Assamese Kamrupa[1] KRDS lects
Dialects	Rajbansi, Kamtapuri, Rangpuri, Deshi, Surjapuri, Dhekri
Language codes
ISO 639-3	–
Glottolog	kamt1242

The speakers are distributed unevenly, as shown in the map.^[2]

The proto-languages of the eastern Magadhan languages. Kamarupa Prakrit corresponds to ?proto-Kamarupa here, a hitherto un-reconstructed proto-language. The period corresponds to earlier than 1250 CE, when proto-Kamta began to innovate unique features.^[3]

These modern lects could be categorised into three groups: western, central and eastern.^[10] Unlike the Assamese, Bengali, Hindi and Nepali languages which were standardised and propagated in the 19th and 20th centuries,^[11] the KRDS lects were not standardised. As a result, the KRDS lects became diglossic vernaculars to these standard varieties and acquired phonological and morphological features from them.^[12]

Nevertheless, two standards are emerging within the KRDS lects: a central Jhapa variety targeting speakers in Nepal, and an eastern Cooch Behar variety targeting speakers in northern West Bengal and western Assam.^[13]

Proto-Kamta

The development of proto-Kamta (also called proto-Kamata) was the result of Sandhya, a ruler of Kamarupa Nagara (North Guwahati), Kamrup moving his capital^[14] to Kamatapur and establishing the Kamata kingdom, thus carrying the native language along with.

Socio-linguistic communities

The modern KRNB lects are spoken primarily in western Assam, northern West Bengal, northern Bangladesh, north-eastern Bihar and south-eastern Nepal.^[9]