When Similar Means Different: Evaluating LLMs on Arabic–Hebrew Cognates

Junhong Liang, Noor Abo Mokh, Bashar Alhafni


Abstract
Arabic and Hebrew, as closely related Semitic languages, share many words with similar surface forms, including true cognates, false friends, and modern loanwords. These lexical relationships create ambiguity for cross-lingual semantic interpretation, as similar forms may correspond to shared, divergent, or borrowed meanings. To evaluate whether LLMs can make these distinctions, we introduce SemCog Bench, a curated benchmark of 1,858 Arabic–Hebrew word pairs with sentence-level annotations for cognate identification and semantic disambiguation. We evaluate a diverse set of open-source and proprietary LLMs across multiple input representations and contextual settings. Our results show reliance on surface-form similarity, with weaker performance on false friends and wide variation on loanwords. We further find that context and scale yield model-dependent gains, while original-script inputs generally perform best. Our findings reveal limitations in cross-lingual form-meaning reasoning and establish SemCog Bench as a benchmark for cross-lingual lexical semantics. Our code and data are publicly available.
Anthology ID:
2026.emnlp-main.424
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
9709–9741
Language:
URL:
https://aclanthology.org/2026.emnlp-main.424/
DOI:
Bibkey:
Cite (ACL):
Junhong Liang, Noor Abo Mokh, and Bashar Alhafni. 2026. When Similar Means Different: Evaluating LLMs on Arabic–Hebrew Cognates. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 9709–9741, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Similar Means Different: Evaluating LLMs on Arabic–Hebrew Cognates (Liang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.424.pdf