Lost in the Mix: Evaluating LLM Understanding of Code-Switched Text
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Abstract (arXiv)
Code-switching (CSW) is the act of alternating between two or more languages within a single discourse. This phenomenon is widespread in multilingual communities, and increasingly prevalent in online content, where users naturally mix languages in everyday communication. As a result, Large Language Models (LLMs), now central to content processing and generation, are frequently exposed to code-switched inputs. Given their widespread use, it is crucial to understand how LLMs process and reason about such mixed-language text. This paper presents a systematic evaluation of LLM comprehension under code-switching by generating CSW variants of established reasoning and comprehension benchmarks. While degradation is evident when foreign tokens disrupt English textunicodex2013even under linguistic constraintsunicodex2013embedding English into other languages often improves comprehension. Though prompting yields mixed results, fine-tuning offers a more stable path to degradation mitigation.
Key facts. Cited by 10 papers in the map (data through 14 Oct 2026). Builds on 30 of its 52 references that are in the map. First posted on arXiv 16 Jun 2025.
Builds on
30 of 52 references.
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18 more
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Built on by
Citing papers per year: 2025: 5; 2026: 5.
10 papers.
- 2025Culture is Everywhere: A Call for Intentionally Cultural Evaluationcited by 10
- 2025On the Entity-Level Alignment in Crosslingual Consistencycited by 4
- 2025Gradual Code-Switching as Inference-Time Cross-Lingual Representational Alignment for LLMscited by 3
- 2025Towards Fine-Grained Code-Switch Speech Translation with Semantic Space Alignmentcited by 1
- 2026Position: the Stochastic Parrot in the Coal Mine. Model Collapse is a Threat to Low-Resource Communitiescited by 1
- 2026Code-Switching Reveals Language Anchoring in Multilingual LLMscited by 1
- 2025Efficient Training of Robust Traditional Chinese LLaMA-1B on a Single Consumer GPU: Continual Pre-training, SFT, and DPOcited by 0
- 2026Code Mixologist : A Practitioner's Guide to Building Code-Mixed LLMscited by 0
- 2026BrailleBench: Investigating Multi-Criteria Braille Comprehension in Large Language Modelscited by 0
- 2026CSWBench: Evaluating Context-Sensitive Code-Switching in Creative Writingcited by 0
- 2026CSWBench: Evaluating Context-Sensitive Code-Switching in Creative Writing14 Oct 2026
- 2026BrailleBench: Investigating Multi-Criteria Braille Comprehension in Large Language Models27 Aug 2026
- 2026Code-Switching Reveals Language Anchoring in Multilingual LLMs18 Jun 2026
- 2026Position: the Stochastic Parrot in the Coal Mine. Model Collapse is a Threat to Low-Resource Communities5 May 2026
- 2026Code Mixologist : A Practitioner's Guide to Building Code-Mixed LLMs21 Jan 2026
- 2025Towards Fine-Grained Code-Switch Speech Translation with Semantic Space Alignment9 Nov 2025
- 2025On the Entity-Level Alignment in Crosslingual Consistency11 Oct 2025
- 2025Gradual Code-Switching as Inference-Time Cross-Lingual Representational Alignment for LLMs7 Oct 2025
- 2025Efficient Training of Robust Traditional Chinese LLaMA-1B on a Single Consumer GPU: Continual Pre-training, SFT, and DPO2 Oct 2025
- 2025Culture is Everywhere: A Call for Intentionally Cultural Evaluation1 Sep 2025