The Chittagonian Alphabet

Chittagonian (also called Chatgaiya or Chatgaya, ISO 639-3: ctg) is an Indo-Aryan language spoken primarily in Chittagong Division of southeastern Bangladesh. It belongs to the Bengali-Assamese branch of the Indo-Iranian language family — the same branch as Standard Bengali, Assamese, Sylheti, and Rohingya. Chittagonian is spoken by approximately 14–16 million people, making it one of the largest regional languages of Bangladesh by speaker count.

Despite sharing the Bengali script with Standard Bengali, Chittagonian is not mutually intelligible with Standard Bengali. The two languages differ significantly in phonology, vocabulary, and grammar. Chittagonian has a distinct sound system including different vowel qualities, consonant clusters, and tonal features not found in Standard Bengali. Linguists treat Chittagonian as a separate language, and it is listed with its own ISO 639-3 code.

Chittagonian is written in the Bengali script (Unicode Block U+0980–U+09FF) — the same script used for Standard Bengali. 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 hasanta/virama for suppressing vowels, and Bengali-specific digit forms (০–৯).

Because Chittagonian uses the same script as Standard Bengali, Chittagonian text looks visually identical to Bengali text when read by script alone — the difference is in the language and its pronunciation. In addition to the Chittagonian native script, some Chittagonian speakers write informally using the Latin alphabet (romanisation) especially in digital communication, though no standardised romanisation system exists for Chittagonian.

Chittagonian and Standard Bengali differ significantly in several areas. Phonologically, Chittagonian preserves the aspiration distinctions of Bengali consonants but has different vowel qualities — for example, the Chittagonian vowel inventory includes sounds not found in Standard Bengali, and the initial vowel অ is pronounced differently. Chittagonian also has a distinct tone or pitch accent in some words that Standard Bengali lacks.

In vocabulary, Chittagonian has a large proportion of words that differ entirely from their Standard Bengali equivalents — including loanwords from Arakanese/Burmese, local tribal languages, and archaic Indo-Aryan forms. Grammatically, Chittagonian uses different verb forms, pronouns, and sentence structure. Standard Bengali speakers typically cannot understand natural spoken Chittagonian without prior exposure, confirming the two are distinct languages sharing only their script.

Yes, Chittagonian is closely related to Sylheti (ISO 639-3: syl). Both languages belong to the Bengali-Assamese branch of Indo-Aryan and form part of the southeastern dialect continuum of Bangladesh. Sylheti is spoken in Sylhet Division in northeastern Bangladesh, while Chittagonian is spoken in Chittagong Division in southeastern Bangladesh. The two languages share many features that distinguish them from Standard Bengali.

Chittagonian is also related to Rohingya (ISO 639-3: rhg), spoken across the border in Myanmar's Arakan region — reflecting the geographical and historical connections between the Chittagong area and the Arakan coast. Despite these relationships, Sylheti and Chittagonian are distinct languages — they have different phonologies and vocabulary sets, and speakers of one typically find the other difficult to understand without learning it specifically.

Chittagonian is primarily spoken in Chittagong Division of southeastern Bangladesh, which includes Chittagong city (now Chattogram) — the country's main port city and second-largest city — as well as the surrounding districts of Cox's Bazar, Feni, Comilla (partially), and the Chittagong Hill Tracts. Chittagong is one of the most important commercial centres of Bangladesh and a major gateway to the Bay of Bengal.

Large Chittagonian-speaking diaspora communities exist in the United Kingdom (particularly in London and Birmingham, where Bangladeshi communities are concentrated), the Middle East (especially Saudi Arabia, the UAE, Qatar, and Oman, where many Chittagonian speakers work as migrant workers), and other countries. The Chittagonian diaspora maintains the language in community settings, though younger generations often shift to English or Standard Bengali in written communication.

The ISO 639-3 code for Chittagonian is ctg. The language is listed in Glottolog under "Chittagonian" and is classified within the Bengali-Assamese sub-branch of the Eastern Indo-Aryan group. Chittagonian is also known by the local name Chatgaiya (meaning "of Chatgaon/Chittagong") — the name Chatgaon being the traditional Bengali name for Chittagong.

In linguistic databases and language documentation projects, Chittagonian is consistently treated as a language distinct from Standard Bengali (ISO 639-3: ben), Sylheti (ISO 639-3: syl), and Rohingya (ISO 639-3: rhg), although all four belong to the same Bengali-Assamese branch and share many features. The ISO code ctg reflects the SIL International and ISO 639-3 standard classification of Chittagonian as a separate language.