Evaluating the Impact of Verbal Multiword Expressions on Machine Translation

Linfeng Liu, Saptarshi Ghosh, Tianyu Jiang


Abstract
Verbal multiword expressions (VMWEs) remain difficult for machine translation because their meanings are often not recoverable from their component words. In this study, we analyze the impact of three VMWE categories—verbal idioms, verb-particle constructions, and light verb constructions—on machine translation quality from English to multiple languages. Using both established multiword expression datasets and standard machine translation datasets, we evaluate how state-of-the-art translation systems handle these expressions. Our experimental results consistently show that VMWEs negatively affect translation quality, with deeper analysis indicating that this degradation is primarily attributable to the VMWE itself rather than general sentence-level difficulty. We release our code and evaluation framework to test new MT systems for the community.
Anthology ID:
2026.acl-long.698
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
15291–15319
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.698/
DOI:
Bibkey:
Cite (ACL):
Linfeng Liu, Saptarshi Ghosh, and Tianyu Jiang. 2026. Evaluating the Impact of Verbal Multiword Expressions on Machine Translation. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 15291–15319, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Evaluating the Impact of Verbal Multiword Expressions on Machine Translation (Liu et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.698.pdf
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