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Engineering8 min readFeb 18, 2026

Prompt Engineering for Hinglish: A Practical Guide

Standard English LLMs hallucinate on Hinglish queries. Here are the exact techniques we use to make AI agents work reliably in India's most common conversational register.

A
Arjun Mehta
Head of Product
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The Hinglish Problem


"Kal ka appointment 3 baje ke liye book karna hai, Doctor Sharma ke saath — but only if she is available in the evening"


This is a perfectly natural query from an Indian WhatsApp user. Standard GPT-4o-mini gets the intent but struggles with "3 baje" (3 o'clock), "kal" (tomorrow), and the conditional nature of the request.


Our Solution: Few-Shot Hinglish Layer


We inject 8–12 Hinglish examples into every system prompt for India-deployed agents. These are hand-curated from real clinic conversations.


Technique 1: Intent extraction examples


Show the LLM exactly what Hinglish queries look like and what structured intent to extract:


User: "doctor ka time kab hai, aaj"
Intent: { type: "availability_check", doctor: null, date: "today" }

User: "3 baje slot milega kya 10 tarikh ko"  
Intent: { type: "booking_request", time: "15:00", date: "10th" }

Technique 2: Transliteration awareness


LLMs sometimes confuse Hindi transliterations with English words. Explicit disambiguation:


"Kal" = tomorrow (not the name Kal)
"Abhi" = right now (not a name)
"Theek hai" = OK/understood (acknowledgement)

Results


Before: 58% intent accuracy on Hinglish queries.

After 12-example few-shot: 84% intent accuracy.

After Sarvam AI routing for native Hindi: 91%.


The remaining 9% are mixed-script queries (Devanagari + Roman) which we now flag for human review.

EngineeringHinglishPrompt EngineeringIndia
A
Arjun Mehta
Head of Product

Writing about AI automation, India SMBs, and building products that work for the next billion users.

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