Hajong is an Indo-Aryan language^[3] with a possible Tibeto-Burman language substratum.^[4][5] It is spoken by approximately 80,000 ethnic Hajongs across the northeast of the Indian subcontinent, specifically in the states of Assam, Meghalaya, Arunachal Pradesh, and West Bengal in present-day India, and the divisions of Mymensingh and Sylhet in present-day Bangladesh. It is written in Bengali-Assamese script and Latin script.^[2] It has many Sanskrit loanwords. The Hajongs originally spoke a Tibeto-Burman language, but it later mixed with Assamese and Bengali.^[6]

This section does not cite any sources. (January 2020)

The language now spoken by the Hajong people may be considered an Indo-Aryan language because of language shift from a Tibeto-Burman language.^{[citation needed]} Old Hajong or Khati Hajong may have been related to Garo, of Tibeto-Burman origin.

The Hajong Language varies within the clans because of regional variations. There are five notable clans of the Hajong people.

• Doskinâ'
• Korebari
• Susung'yâ'
• Barohazari'
• Miespe'ryâ'

The Hajong language is written by using both the Latin and the Bengali scripts.^[7] Although both scripts are used in India, the Hajongs in Bangladesh expect to use the Bengali script since most education is in Bengali medium.^[8] However, Hajongs living is Dhemaji and surrounding areas use Assamese script. In each script, there is one added unique symbol for the close back unrounded vowel /ɯ/. In Latin script, it is written with "â" or simply a' or e' and in the Eastern Nagari script with "অৗ" at the end of a syllable.^[9]

Hajong has 23 consonant phonemes, 8 vowel phonemes, and 2 approximants that have some characteristics of consonants: /w/ and /j/ act as diphthongs. The vowel phonemes are /a/, /i/, /u/, /e/, /ɛ/, /o/, /ɔ/ and /ɯ/ (close, back, unrounded). Unlike other Indo-Aryan languages, Hajong language has only one 'i' and 'u'. It is somewhat ambiguous whether the final vowel is a phoneme or an allophone of [a] in the environment of other close vowels.^[9] The extra vowel /ɯ/ does not occur in other Indo-Aryan languages but is typical for the Tibeto-Burman family.^[10] Codas j and ch in the final position of a syllable turns into an s sound. Hajong includes some vowel harmony and the devoicing of final consonants.^[9] For separating syllables the apostrophe sign (') or hyphen (-) is used.

Hajong primarily has a canonical word order of subject–object–verb, and the subject, object, and verb of a sentence appear or usually appear in that order. Hajong has a strong tendency to use postpositions, rather than prepositions; to place auxiliary verbs after the action verb; to place genitive noun phrases before the possessed noun; and to have subordinators appear at the end of subordinate clauses.

Hajong is an agglutinative language in which words are often combined and compressed, and there is often no pause between words of a sentence.

Even though it is considered an Eastern Indo-Aryan language, Hajong does not conjugate verbs in the same way as Bengali or Asamiya but rather has a simplified system. The case endings in Hajong are also unique compared to other Indo-Aryan languages and may represent affinity with Tibeto-Burman languages.^[11][5] The following table is taken from Phillips:^[5]

The genitive and unmarked or accusative cases have two forms; re'/ra and le'/la. For words ending with the vowels /a/, /ɛ/ and /ɔ/ it becomes ra and la and for /i/, /u/, /e/, /o/ and /ɯ/ it becomes re' and le'. The vowels /ɛ/(e) and /ɔ/(o) are used to end interrogative sentences, like 'Bhat khase?'(have you taken your food?) and 'Bhat khabo?'(Do you want to eat?); and the vowels /e/(ei) and /o/(ou) are used at the end of declarative sentences, as in 'Bhat khasei.'([I] have taken my food.) and 'Bhat Khabou'([I] will eat.). Adding the suffix be' or ba to interrogative words turn them into indefinite pronouns; for example, kibe' means something, kei'be' means someone, kumaba means somewhere and also ke'ibe', kageba, kunde'be' and kalaba means 'I don't know who/whom/which/whose' respectively in English. Similarly adding the suffix ha and ga to verbs means 'come and (verb)' and 'go and (verd)' respectively; for example, khaha means come and eat, niha means come and take; khaga means go and eat and niga means go and take.