Low-Resource Dialect Adaptation of Large Language Models: A French Dialect Case-Study

Eeham Khan, Firas Saidani, Owen Van Esbroeck, Richard Khoury, Leila Kosseim


Abstract
Despite the widespread adoption of Large Language Models (LLMs), their strongest capabilities remain largely confined to a small number of high-resource languages for which there is abundant training data. Recently, continual pre-training (CPT) has emerged as a means to fine-tune these models to low-resource regional dialects. In this paper, we study the use of CPT for dialect learning under tight data and compute budgets. Using low-rank adaptation (LoRA) and compute-efficient continual pre-training, we adapt three LLMs to the Québec French dialect using a very small dataset and benchmark them on the COLE suite. Our experiments demonstrate an improvement on the minority dialect benchmarks with minimal regression on the prestige language benchmarks with around 1% of model parameters updated. Analysis of the results demonstrate that gains are highly contingent on corpus composition. These findings indicate that CPT with parameter-efficient fine-tuning (PEFT) can narrow the dialect gap by providing cost-effective and sustainable language resource creation, expanding high-quality LLM access to minority linguistic communities. To support reproducibility and broaden access, we release the first Québec French LLMs on Hugging Face.
Anthology ID:
2026.lrec-main.840
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
10723–10734
Language:
URL:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.840/
DOI:
Bibkey:
Cite (ACL):
Eeham Khan, Firas Saidani, Owen Van Esbroeck, Richard Khoury, and Leila Kosseim. 2026. Low-Resource Dialect Adaptation of Large Language Models: A French Dialect Case-Study. International Conference on Language Resources and Evaluation, main:10723–10734.
Cite (Informal):
Low-Resource Dialect Adaptation of Large Language Models: A French Dialect Case-Study (Khan et al., LREC 2026)
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PDF:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.840.pdf