LLMs Got Rhyme? Hybrid Phonological Filtering for Greek Poetry Rhyme Detection and Generation

Stergios Chatzikyriakidis, Anastasia Natsina


Abstract
Large Language Models (LLMs), even though exhibiting multiple capabilities on many NLP tasks, struggle with phonologically-grounded phenomena like rhyme detection and generation. When one moves to lower-resource languages such as Modern Greek, this is even more evident. In this paper, we present a hybrid neural-symbolic system that combines LLMs with deterministic phonological algorithms to achieve accurate rhyme identification and generation. We implement a comprehensive taxonomy of Greek rhyme types and employ an agentic generation pipeline with phonological verification. We use multiple prompting strategies (zero-shot, few-shot, Chain-of-Thought, and RAG-augmented) across several LLMs including Claude 3.7 and 4.5, GPT-4o, Gemini 2.0 and open-weight models like Llama 3.1 8B and 70B and Mistral Large. Results reveal a significant reasoning gap: while native-like models (Claude 3.7) perform intuitively (40\% accuracy in identification), reasoning-heavy models (Claude 4.5) achieve state-of-the-art performance (54\%) only when prompted with Chain-of-Thought. Most critically, pure LLM generation fails significantly (under 4\% valid poems), while our hybrid verification loop restores performance to 73.1\%. Along with the system presented, we further release a corpus of 40,000+ rhymes, derived from the \textit{Anemoskala} and \textit{Interwar Poetry} corpora, to support future research.
Anthology ID:
2026.latechclfl-1.9
Volume:
Proceedings of the 10th Joint SIGHUM Workshop on Computational Linguistics for Cultural Heritage, Social Sciences, Humanities and Literature 2026
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Diego Alves, Yuri Bizzoni, Stefania Degaetano-Ortlieb, Anna Kazantseva, Janis Pagel, Stan Szpakowicz
Venues:
LaTeCH-CLfL | WS
SIG:
SIGHUM
Publisher:
Association for Computational Linguistics
Note:
Pages:
87–101
Language:
URL:
https://aclanthology.org/2026.latechclfl-1.9/
DOI:
Bibkey:
Cite (ACL):
Stergios Chatzikyriakidis and Anastasia Natsina. 2026. LLMs Got Rhyme? Hybrid Phonological Filtering for Greek Poetry Rhyme Detection and Generation. In Proceedings of the 10th Joint SIGHUM Workshop on Computational Linguistics for Cultural Heritage, Social Sciences, Humanities and Literature 2026, pages 87–101, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
LLMs Got Rhyme? Hybrid Phonological Filtering for Greek Poetry Rhyme Detection and Generation (Chatzikyriakidis & Natsina, LaTeCH-CLfL 2026)
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PDF:
https://aclanthology.org/2026.latechclfl-1.9.pdf