Thēthi

Thēthi, also known as Thēth, Thethiya, Thenthi, or Thati, is a Maithili dialect, mainly spoken in the Mithila region of India and Nepal.^[1][2] It is spoken mainly in Munger divisions of Bihar, India and in Koshi Province of Nepal.^[3] It has 165,000 speakers in India according to the 2011 census.^[4]

Thēthi
ठेठी मैथिली • Thethi Maithili
The name of Thēthi written in Tirhuta
Native to	India, Nepal
Region	Mithila
Ethnicity	Maithils
Native speakers	1,65,420
Language family	Indo-European Indo-Iranian Indo-Aryan Eastern Bihari Maithili Thēthi
Language codes
ISO 639-3	–
Glottolog	tati1242  Tati (Maithili)

Distinction from Central Maithili

In the Eastern Indo-Aryan languages—Bangla, Maithili, Assamese, and Odia —The vowel অ underwent a historical shift to [ɔ] (a rounded “aw/o” sound, like in English off). Linguists explain this as the Eastern Indo-Aryan vowel shift, likely caused by substrate influence from pre-Indo-Aryan languages in Bengal and Mithila that lacked [ə], along with the natural tendency for [ə] to drift into a clearer [ɔ] in rapid speech. As a result, speakers of Bangla and Thēthi Maithili pronounce অ as “O” like, while Hindi and related languages kept it as “A/uh.^[5]

Name (Spelling) Maithili Pronunciation

Amit → pronounced Omit [ɔmit]

Ajay → pronounced Ojoy [ɔdʒɔj]

Amar → pronounced Omar [ɔmər]

Jay → pronounced Joy [dʒɔj]

Speakers of Central Maithili (Darbhanga–Madhubani belt) often describe Thēthi as a plainer or rougher form of Maithili. Linguistically, Thēthi retains the core features of Maithili, including its Indo-Aryan roots derived from Magadhi Apabhramsha through Abahattha. However, it exhibits unique phonetic and lexical traits. For instance, Thethi tends to preserve traditional Maithili phonetic links but may show variations in pronunciation and vocabulary influenced by its geographic proximity to other regional languages like Bengali. For example, the phrase (it was done) will be pronounced as bha gēlaī in Central Maithili. Whereas, in Thēthi, it will be pronounced as bhæy gēlaī.

Some of the verb forms that are used in central Maithili are also dropped in Thēthi. For example, instead of (Achhi/Aichh, meaning 'is'), a more colloquial variant (chhai/chhiyai) is preferred.

Vocabulary wise, Thēthi may show an influence of Bengali for some part, which are spoken alongside it in the region. Although, the tatsama words of Central Maithili still dominate its vocabulary.