Turning English-centric LLMs Into Polyglots: How Much Multilinguality Is Needed?

Tannon Kew, Florian Schottmann, Rico Sennrich


Abstract
The vast majority of today’s large language models (LLMs) are English-centric, having been pretrained predominantly on English text. Yet, in order to meet user expectations, models need to be able to respond appropriately in multiple languages once deployed in downstream applications. This requires strong cross-lingual transfer abilities.In this work, we investigate the minimal amount of multilinguality required during finetuning to elicit cross-lingual generalisation in English-centric LLMs. In experiments across four LLMs, we find that multilingual instruction tuning with as few as two to three languages is both necessary and sufficient to elicit effective cross-lingual generalisation, with the limiting factor being the degree to which a target language is seen during pretraining. Evaluations on five different tasks further reveal that multilingual instruction tuning is most beneficial for generative tasks that assume input/output language agreement, such as in chat settings, while being of less importance for highly structured classification-style tasks.
Anthology ID:
2024.findings-emnlp.766
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2024
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
13097–13124
Language:
URL:
https://preview.aclanthology.org/build-pipeline-with-new-library/2024.findings-emnlp.766/
DOI:
10.18653/v1/2024.findings-emnlp.766
Bibkey:
Cite (ACL):
Tannon Kew, Florian Schottmann, and Rico Sennrich. 2024. Turning English-centric LLMs Into Polyglots: How Much Multilinguality Is Needed?. In Findings of the Association for Computational Linguistics: EMNLP 2024, pages 13097–13124, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Turning English-centric LLMs Into Polyglots: How Much Multilinguality Is Needed? (Kew et al., Findings 2024)
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PDF:
https://preview.aclanthology.org/build-pipeline-with-new-library/2024.findings-emnlp.766.pdf