Poro 34B and the Blessing of Multilinguality




Luukkonen, Risto; Burdge, Jonathan; Zosa, Elaine; Talman, Aarne; Komulainen, Ville; Hatanpää, Väinö; Sarlin, Peter; Pyysalo, Sampo

Johansson, Richard; Stymne, Sara

Nordic Conference on Computational Linguistics and Baltic Conference on Human Language Technologies

2025

 NEALT proceedings series

Proceedings of the Joint 25th Nordic Conference on Computational Linguistics and 11th Baltic Conference on Human Language Technologies (NoDaLiDa/Baltic-HLT 2025)

57

367

382

978-9908-53-109-0

1736-8197

1736-6305

https://aclanthology.org/2025.nodalida-1.40/

https://research.utu.fi/converis/portal/detail/Publication/506554658



The pretraining of state-of-the-art large language models now requires trillions of words of text, which is orders of magnitude more than available for the vast majority of languages. While including text in more than one language is an obvious way to acquire more pretraining data, multilinguality is often seen as a curse, and most model training efforts continue to focus near-exclusively on individual large languages. We believe that multilinguality can be a blessing: when the lack of training data is a constraint for effectively training larger models for a target language, augmenting the dataset with other languages can offer a way to improve over the capabilities of monolingual models for that language. In this study, we introduce Poro 34B, a 34 billion parameter model trained for 1 trillion tokens of Finnish, English, and programming languages, and demonstrate that a multilingual training approach can produce a model that substantially advances over the capabilities of existing models for Finnish and excels in translation, while also achieving competitive performance in its class for English and programming languages. We release the model parameters, scripts, and data under open licenses at https://huggingface.co/LumiOpen/Poro-34B.


This project has received funding from the European Union’s Horizon Europe research and innovation programme under Grant agreement No 101070350.


Last updated on 28/01/2026 12:51:59 PM