YallaMorph: A Benchmark for Evaluating Arabic Morphological Generation in Large Language Models

Mahmoud Reda, Salam Khalifa, Reham Marzouk, Nizar Habash


Abstract
Arabic morphology remains challenging for large language models, since fluent generation does not guarantee accurate morphosyntactic control. Existing Arabic evaluations mainly target downstream tasks and do not directly test controlled morphological generation from explicit lexical and feature-based input. We introduce YallaMorph, a large-scale benchmark for Arabic morphological generation covering verbs, nouns, adjectives, their cliticized forms, and invalid configurations. We evaluate multilingual and Arabic-oriented LLMs under diacritized and undiacritized settings over 600K benchmark entries. Results show that Arabic morphological generation remains difficult, especially for cliticized, unseen, and morphologically rare forms.
Anthology ID:
2026.findings-emnlp.2035
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
43299–43315
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2035/
DOI:
10.18653/2026.findings-emnlp.2035
Bibkey:
Cite (ACL):
Mahmoud Reda, Salam Khalifa, Reham Marzouk, and Nizar Habash. 2026. YallaMorph: A Benchmark for Evaluating Arabic Morphological Generation in Large Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 43299–43315, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
YallaMorph: A Benchmark for Evaluating Arabic Morphological Generation in Large Language Models (Reda et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2035.pdf