UrBLiMP: A Benchmark for Evaluating the Linguistic Competence of Large Language Models in Urdu

Farah Adeeba, Brian Dillon, Hassan Sajjad, Rajesh Bhatt


Abstract
Evaluating how large language models (LLMs) capture the grammatical structure of low-resource languages remains underexplored. This paper presents the Urdu Benchmark of Linguistic Minimal Pairs (UrBLiMP)—a diagnostic suite of 5,696 minimal pairs that contrast grammatical acceptability across ten core syntactic and morpho-syntactic phenomena in Urdu. The dataset is constructed from the Urdu Treebank and diverse text corpora, and human validation achieves a 96.1% inter-annotator agreement, confirming its reliability. We evaluate twenty one multilingual LLMs, including LLaMA-3-70B and Gemma-3-27B-PT, and additionally assess the proprietary GPT-4o model using grammar-prompting techniques. GPT-4o (grammar-prompted) attains the highest average accuracy (97.4%), reaching near-human performance on regular phenomena such as aspect agreement and ergativity. However, all models continue to struggle with flexible syntactic patterns like word-order variation and long-distance subject–verb agreement. UrBLiMP provides the first controlled evaluation framework for probing morpho-syntactic competence in Urdu and highlights both the progress and remaining challenges of multilingual and proprietary LLMs in low-resource settings.
Anthology ID:
2026.findings-acl.29
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
602–617
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.29/
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Cite (ACL):
Farah Adeeba, Brian Dillon, Hassan Sajjad, and Rajesh Bhatt. 2026. UrBLiMP: A Benchmark for Evaluating the Linguistic Competence of Large Language Models in Urdu. In Findings of the Association for Computational Linguistics: ACL 2026, pages 602–617, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
UrBLiMP: A Benchmark for Evaluating the Linguistic Competence of Large Language Models in Urdu (Adeeba et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.29.pdf
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