The Limbu Alphabet

The Limbu Sirijanga script (also called Kirat Sirijanga or Yakthung Sirijanga) is an abugida encoded in the Limbu Unicode Block (U+1900–U+194F). It is written left to right and has an unusual inherent vowel of /ɔ/ — in contrast to virtually all other South Asian abugidas (Devanagari, Bengali, etc.), which use /a/ as the inherent vowel.

The script encodes 31 consonant letters, 9 vowel signs, 9 small-letter finals, and 10 digits. Its most distinctive typographic features are the small letter forms for the 8 most common final consonants (k, ng, t, n, p, m, r, l) — each a compact, vowelessly-rendered version of the full letter — and two circumgraph vowel signs (E and O) that appear on both sides of their base consonant simultaneously.

Limbu is spoken by approximately 407,000 people: about 366,200 in Nepal (2011 census), mainly in the Koshi and Mechi zones of eastern Nepal — the districts of Taplejung, Panchthar, Ilam, Tehrathum, Dhankuta, and Sunsari. About 40,800 speakers live in India, primarily in Sikkim, Darjeeling, and Kalimpong in West Bengal, as well as Assam and Nagaland.

The Limbu people call themselves the Yakthung and have a distinct cultural identity in the Himalayan region. Unlike many minority languages, Limbu has an active writing tradition maintained through schools, community organisations, and media. The language is taught at primary and secondary school levels in eastern Nepal and in Sikkim, India.

The Limbu script is traditionally attributed to the legendary Limbu king Sirijanga Hang, said to have lived in the 9th century CE. After falling into disuse, the script was famously revived in the 18th century CE by the cultural hero Te-ongsi Sirijunga Xin Thebe (also called Sirijunga), who is venerated as the great reformer and promoter of Limbu script and literature. He was eventually martyred for his cultural work.

The modern standardised form of the script was established in 1925 in Kalimpong by Iman Singh Chemjong and was further refined in the 1970s. Limbu scholars believe the script may have been influenced by or modelled on the Lepcha script, which was itself derived from the Tibetan alphabet. The Limbu script is used in the Mundhum, the sacred oral and written tradition of the Kiranti peoples.

Limbu belongs to the Kiranti branch of the Sino-Tibetan language family. Kiranti is a group of approximately 30 closely related languages spoken in the hill regions of eastern Nepal and the adjoining areas of northeast India — including Rai languages (Bantawa, Chamling, Kulung, and others) and Limbu. All Kiranti languages share features of verbal morphology and lexical descent from a common ancestor.

Within Kiranti, Limbu (Yakthung) is the westernmost major member and the one with the largest number of speakers. It is notably distinct from Nepali (an Indo-Aryan language) and Tibetan (a different Tibeto-Burman branch) despite geographic proximity to both. Limbu has its own distinctive phonology including a system of phonemic distinctions that differs from both Indo-Aryan and Tibetic patterns.

The Limbu script has several features that distinguish it from most other South Asian abugidas. First, the inherent vowel is /ɔ/, not /a/ — meaning every bare consonant letter in Limbu represents a syllable ending in /ɔ/ by default. Second, the script has a dual system for final consonants: the 8 most common finals (k, ng, t, n, p, m, r, l) each have a dedicated "small letter" form (U+1930–U+1938) that can be written at syllable-final position without needing a virama.

Third, two vowel signs — E (ᤧ, U+1927) and O (ᤨ, U+1928) — are circumgraphs: each is encoded as a single code point but visually renders as two separate glyphs appearing on both the left and right (or above and below) of the base consonant simultaneously. This is a complex Unicode rendering feature requiring advanced font support. Fourth, three medial subjoined consonants (-y-, -r-, -w-) mark consonant clusters within syllables.

Yes — compared to many minority scripts of South Asia, Limbu is relatively well-maintained in education and media. In Nepal, Limbu is taught at primary and secondary school level in eastern districts, and there are Limbu-language radio programmes, newspapers, and cultural publications. The Limbu Cultural Corporation and various Yakthung cultural organisations promote language education and publication.

In Sikkim, India, Limbu is one of the state's recognised languages and is taught in schools. The language also features in community radio broadcasts and has a growing digital presence. The Mundhum — the sacred oral literature of the Kiranti peoples — has been partially transcribed in Limbu script, helping to document cultural heritage alongside the daily use of the language.