# Does your coding agent understand you in your native language?

> Source: <https://dev.to/tech-vexy/does-your-coding-agent-understand-you-in-your-native-language-1a4k>
> Published: 2026-10-10 22:37:48+00:00

*This is a submission for the [Kaggle Benchmarking Challenge](https://dev.to/challenges/kaggle-2026-09-23)*

I build AI tools for developers and learners in Kenya, so I kept asking one question: if you brief a coding agent in a language it barely saw in training, does it still do the job?

I tested six languages: English, Chinese, French, Spanish, Swahili, and **Maragoli** (Lulogooli), a Luhya language spoken in western Kenya. I wrote the Maragoli prompts myself.

**Task 1: Coding.** 5 small Python problems, each described in all 6 languages (30 prompts per model). Function names, signatures and unit tests stay identical, so only the instruction language changes. Score = unit-test pass rate.

**Task 2: Planning.** A good agent plans before it codes, and planning means asking the user clarifying questions. I gave 3 deliberately vague requests ("build me a small app to track my expenses", "write a script that cleans up my files", "make a website for my shop") in all 6 languages, each ending with: *make a short plan, ask clarifying questions, and do not write code yet.* I check whether the model asks a question, follows "no code yet", and replies in the language it was spoken to.

Task 1 is a control: the English code scaffolding makes the language barrier easy to cross. Task 2 removes that scaffolding.

16 models ran Task 1, and 7 also completed Task 2: Claude Haiku 5.5 and Sonnet 5.5, GPT-6.1 Sol, Gemini 3.1 Pro Preview , a Gemini 3.8 Flash model, GLM-5 and gpt-oss-120b. I picked a spread of providers and sizes, including Chinese-lab models (GLM, Qwen, DeepSeek). Opus 5.5 and GPT-6 Astra scored 100% on Task 1 but could not run Task 2 (free quota), so the "0" on their leaderboard Overall reflects a failed run, not their ability. Grok was not available on the platform.

**Short answer: for code, mostly yes. For a conversation in Maragoli, no.**

**Task 1.** 11 of 16 models scored 100%. The rest: gpt-oss-120b, GLM-5 and Gemma 4 31B at 96.7%, gpt-oss-20b at 93.3%, and Qwen3 Next 80B Thinking at 86.7%. The language barrier barely mattered, because the code scaffolding was in English.

**Task 2, Maragoli prompts (7 models x 3 prompts = 21 replies):**

| Model | Replied in Maragoli* | English or Swahili | Another language | Followed "no code yet" | 
|---|---|---|---|---|
| Claude Haiku 5.5 | 0/3 | 3 | 0 | 2/3 | 
| Claude Sonnet 5.5 | 0/3 | 2 | 1 | 3/3 | 
| GPT-6.1 Sol | 0/3 | 3 | 0 | 3/3 | 
| Gemini 3.1 Pro Preview | 0/3 | 3 | 0 | 3/3 | 
| Gemini 3.8 Flash | 0/3 | 2 | 1 | 3/3 | 
| GLM-5 | 0/3 | 3 | 0 | 1/3 | 
| gpt-oss-120b | 0/3 | 3 | 0 | 2/3 | 

*Keyword heuristic, see limits.

In my earlier local test runs (Gemini 3.8 Flash Preview), the failures were concrete: it read the negation word *dave* ("not") as a person's name and greeted me as "Dave", built a data-usage tracker instead of an expense tracker, and answered one prompt in Shona and another in Kirundi. Models may be matching words like *riduka* ("shop") to the nearest language they know, but that is a guess from a tiny sample.

**What surprised me:** the code task hid the problem completely. A model that passes every unit test can still be unable to talk to the person asking.

**What I would measure next:** more and harder problems, multi-turn agent tasks where the user answers back, a proper language identifier validated by native speakers, and more Luhya varieties and other Kenyan languages.

[https://www.kaggle.com/benchmarks/eveliaveldrine/language-barrier-benchmark](https://www.kaggle.com/benchmarks/eveliaveldrine/language-barrier-benchmark)

If you speak Maragoli or another Luhya variety and see something wrong in my prompts, tell me in the comments.
