Beyond English: The Impact of Prompt Translation Strategies across Languages and Tasks in Multilingual LLMs

Itai Mondshine, Tzuf Paz-Argaman, Reut Tsarfaty


Abstract
Despite advances in the multilingual capabilities of Large Language Models (LLMs) across diverse tasks, English remains the dominant language for LLM research and development. So, when working with a different language, this has led to the widespread practice of pre-translation, i.e., translating the task prompt into English before inference. Selective pre-translation, a more surgical approach, focuses on translating specific prompt components. However, its current use is sporagic and lacks a systematic research foundation. Consequently, the optimal pre-translation strategy for various multilingual settings and tasks remains unclear. In this work, we aim to uncover the optimal setup for pre-translation by systematically assessing its use. Specifically, we view the prompt as a modular entity, composed of four functional parts: instruction, context, examples, and output, either of which could be translated or not. We evaluate pre-translation strategies across 35 languages covering both low and high-resource languages, on various tasks including Question Answering (QA), Natural Language Inference (NLI), Named Entity Recognition (NER), and Abstractive Summarization. Our experiments show the impact of factors as similarity to English, translation quality and the size of pre-trained data, on the model performance with pre-translation. We suggest practical guidelines for choosing optimal strategies in various multilingual settings
Anthology ID:
2025.findings-naacl.73
Volume:
Findings of the Association for Computational Linguistics: NAACL 2025
Month:
April
Year:
2025
Address:
Albuquerque, New Mexico
Editors:
Luis Chiruzzo, Alan Ritter, Lu Wang
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
1331–1354
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URL:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.73/
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Cite (ACL):
Itai Mondshine, Tzuf Paz-Argaman, and Reut Tsarfaty. 2025. Beyond English: The Impact of Prompt Translation Strategies across Languages and Tasks in Multilingual LLMs. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 1331–1354, Albuquerque, New Mexico. Association for Computational Linguistics.
Cite (Informal):
Beyond English: The Impact of Prompt Translation Strategies across Languages and Tasks in Multilingual LLMs (Mondshine et al., Findings 2025)
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https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.73.pdf