Why Better Cross-Lingual Alignment Fails for Better Cross-Lingual Transfer: Case of Encoders

Yana Veitsman, Yihong Liu, Hinrich Schuetze


Abstract
Cross-lingual alignment is often assumed to improve cross-lingual transfer by bringing representations of different languages closer together. However, improvements in representational alignment do not consistently translate into better downstream performance. We investigate this disconnect using XLM-R models explicitly aligned across four language pairs with token-level, sentence-level, and masked-language-modeling objectives. We evaluate their zero-shot transfer on a token-level task (part-of-speech tagging) and a sentence-level task (sentence classification), and analyze both representational changes and the gradients induced by the alignment and downstream objectives. We find that embedding-based alignment metrics do not reliably indicate whether alignment will improve or degrade downstream performance. Moreover, alignment and downstream-task gradients are often nearly orthogonal, particularly when the alignment objective and downstream task operate at different representational levels. These findings suggest that representation alignment alone is insufficient for assessing cross-lingual transfer, and that the compatibility between alignment and downstream objectives should be considered when designing or evaluating alignment methods.
Anthology ID:
2026.mrl-1.10
Volume:
Proceedings of the 6th Workshop on Multilingual Representation Learning (MRL 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
David Ifeoluwa Adelani, Jesujoba Alabi, Catherine Arnett, Tyler Chang, C.M. Downey, Omer Goldman, Senyu Li, Lester James Validad Miranda, Jirui Qi, David Stap, Genta Indra Winata, Xinyu Crystina Zhang
Venues:
MRL | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
119–134
Language:
URL:
https://aclanthology.org/2026.mrl-1.10/
DOI:
Bibkey:
Cite (ACL):
Yana Veitsman, Yihong Liu, and Hinrich Schuetze. 2026. Why Better Cross-Lingual Alignment Fails for Better Cross-Lingual Transfer: Case of Encoders. In Proceedings of the 6th Workshop on Multilingual Representation Learning (MRL 2026), pages 119–134, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Why Better Cross-Lingual Alignment Fails for Better Cross-Lingual Transfer: Case of Encoders (Veitsman et al., MRL 2026)
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PDF:
https://aclanthology.org/2026.mrl-1.10.pdf