ChakmaNMT: Machine Translation for a Low-Resource and Endangered Language via Transliteration

Aunabil Chakma, Aditya Chakma, Masum Hasan, Soham Khisa, Chumui Tripura, Rifat Shahriyar


Abstract
We present a systematic study of machine translation for Chakma, an endangered and extremely low-resource Indo-Aryan language. We introduce a large Chakma–Bangla machine translation resource comprising 15,021 parallel translation pairs, 42,783 Chakma monolingual sentences, and a trilingual evaluation benchmark. To address data scarcity and the script mismatch between Chakma and Bangla, we develop a character-level transliteration framework that enables transfer from Bangla and multilingual pretrained models. We evaluate from-scratch machine translation systems, fine-tuned pretrained models, and large language models using in-context learning. Our results show that transliteration is crucial for the tested pretrained models and that performance is strongly direction-dependent: in-context learning performs best for Chakma-to-Bangla translation, while Bangla-to-Chakma remains considerably more challenging, with the strongest approach depending on the evaluation metric.
Anthology ID:
2026.wmt-main.5
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
64–81
Language:
URL:
https://aclanthology.org/2026.wmt-main.5/
DOI:
Bibkey:
Cite (ACL):
Aunabil Chakma, Aditya Chakma, Masum Hasan, Soham Khisa, Chumui Tripura, and Rifat Shahriyar. 2026. ChakmaNMT: Machine Translation for a Low-Resource and Endangered Language via Transliteration. In Proceedings of the Eleventh Conference on Machine Translation, pages 64–81, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ChakmaNMT: Machine Translation for a Low-Resource and Endangered Language via Transliteration (Chakma et al., WMT 2026)
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PDF:
https://aclanthology.org/2026.wmt-main.5.pdf