The Kamtapuri Alphabet

Kamtapuri (ISO 639-3: rkt), also called Koch or Rajbangshi, is an Eastern Indo-Aryan language spoken in North Bengal, India — primarily in the Cooch Behar, Jalpaiguri, and Darjeeling districts. It is also spoken in parts of Assam and in northern Bangladesh. Kamtapuri belongs to the Bengali-Assamese branch of the Indo-Iranian language family, the same branch that includes Standard Bengali, Assamese, and Chittagonian. Estimates of speaker population range from 5 to 10 million depending on the classification used.

The name Kamtapuri derives from the historic Kamata Kingdom and the Koch Bihar princely state of North Bengal. The Koch-Rajbangshi people are the primary speakers, and the language carries strong cultural significance for this ethnic community. Kamtapuri shares the ISO 639-3 code rkt with Rangpuri — some linguists consider Kamtapuri and Rangpuri to be dialects of the same language, while others classify them as distinct varieties based on geographic and phonological differences.

Kamtapuri is written in the Bengali script (Unicode Block U+0980–U+09FF) — the same script used for Standard Bengali and Assamese. The Bengali script is a Brahmic abugida, written left to right. It includes 36 consonant letters, 11 independent vowel letters, a set of vowel diacritics (কার, kar), the chandrabindu (ঁ) for nasalisation, the hasanta/virama for suppressing inherent vowels, and Bengali-specific digit forms (০–৯).

Because Kamtapuri uses the same script as Standard Bengali, written Kamtapuri text is visually identical to Bengali script. Informal digital communication by Kamtapuri speakers may also use the Latin alphabet, though no standardised romanisation system has been officially adopted. The shared script with Bengali facilitates literacy transfer between the two languages for educated speakers of both.

Kamtapuri and Standard Bengali differ significantly in phonology, vocabulary, and grammar. Phonologically, Kamtapuri preserves a distinct North Bengali accent with features such as final consonant dropping, vowel centralisation, and unique pitch patterns not found in Standard Bengali. The initial vowel অ is realised differently, and Kamtapuri has several phonological mergers absent in Standard Bengali.

In vocabulary, Kamtapuri retains many archaic Indo-Aryan words and has absorbed vocabulary from the indigenous Koch tribal heritage, giving it a distinct lexical character. Grammatically, Kamtapuri uses different verb forms, honorific systems, and pronoun paradigms. Despite sharing the Bengali script, the two languages have low mutual intelligibility in natural spoken form, confirming their status as distinct linguistic varieties.

Kamtapuri and Rangpuri are very closely related — both carry the ISO 639-3 code rkt and are often treated as varieties of the same language in linguistic databases. Both are spoken by the Koch-Rajbangshi community of North Bengal and share the same Bengali script, core grammar, and much of their vocabulary. The primary distinction is geographic: Kamtapuri is more specifically associated with the Cooch Behar and Jalpaiguri districts of North Bengal, while Rangpuri extends across the broader Rangpur region including parts of northern Bangladesh and Assam.

The shared ISO code and overlapping speaker population mean that speaker estimates are often combined. Some linguists and community advocates distinguish Kamtapuri as a separate literary and cultural identity linked to the historic Kamata Kingdom, while Rangpuri is associated with the Rangpur plains. Both varieties are closely related to Rajbongshi (ISO 639-3: rjs), forming a dialect continuum across North Bengal and Assam.

Kamtapuri is primarily spoken in the Cooch Behar, Jalpaiguri, and Darjeeling districts of North Bengal, West Bengal, India. The Cooch Behar district, historically the site of the Koch Bihar princely state, is the cultural heartland of Kamtapuri speakers. The language is also spoken across the border in Assam (particularly in the Bongaigaon and Dhubri areas) and in northern Bangladesh (Rangpur Division).

Kamtapuri speakers form a significant portion of the population in the Dooars and Terai regions of North Bengal, an area of great cultural and ecological diversity at the foothills of the Himalayas. There are also diaspora communities in other Indian cities. The Koch-Rajbangshi community — the primary speakers of Kamtapuri — have historically campaigned for linguistic and ethnic recognition within India, including demands for the inclusion of Kamtapuri/Rajbangshi in the Eighth Schedule of the Indian Constitution.

The ISO 639-3 code for Kamtapuri is rkt, shared with Rangpuri. This shared code reflects the close linguistic relationship between the two varieties. In Glottolog, Kamtapuri is documented under the languoid identifier "kamt1241". Kamtapuri is also known by the endonyms Koch, Rajbangshi, and Kamrupi in different scholarly and community contexts.

The language is listed separately from Standard Bengali (ISO 639-3: ben) and Assamese (ISO 639-3: asm), reflecting its distinct phonological and lexical character as a regional language of the Eastern Indo-Aryan branch. Rajbongshi (ISO 639-3: rjs) is a closely related but separately coded language, reflecting the complex dialect continuum of the North Bengal and Assam region.