### Answer For multilingual support with French, Spanish, and English, you should set the

language

parameter to

multi

for multilingual support. [(1) ]() [(2) ]() [(3) ]() Key settings to address your issues: 1. **Language Setting**: Set

language

to

"multi"

to enable multilingual support. [(1) ]() 2. **Speech Normalization**: Enable

normalize_for_speech

set to

true

- this converts entities like numbers, currency, and dates into spoken form for more consistent speech synthesis, which should help with the number pronunciation issues in Spanish. [(1) ]() [(2) ]() 3. **Boosted Keywords**: You can use

boosted_keywords

to bias the transcriber toward specific words or phrases that are commonly misrecognized. Regarding language switching issues: The multilingual feature currently supports seamlessly switching between English, Spanish, French, German, Hindi, Russian, Portuguese, Japanese, Italian, and Dutch (using nova 3) . [(4) ]() Prompt recommendations: In your Global Prompt, you should explicitly instruct the agent to: - Detect and respond in the same language the user is speaking - Not switch languages unless the user switches first For number pronunciation: Speech Normalization is specifically designed to help with this - it will "convert entities like date, currency, numbers into plain words, which can help prevent issues where audio generated was not pronouncing those right." [(5) ]() Check out these pote

ntially useful sources for more details: - [Step 2: Configure the basic settings]() - [Update Voice Agent]() - [Platform Changelogs | Retell AI]() Would you like a general answer on prompt engineering techniques for multilingual agents?

​ To learn more, see the sources I considered: [[1] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[2] List Voice Agents](https://docs.retellai.com/api-references/list-agents) [[3] Create Voice Agent](https://docs.retellai.com/api-references/create-agent) [[4] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) [[5] Step 2: Configure the basic settings](https://docs.retellai.com/build/single-multi-prompt/configure-basic-settings) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

Thanks for the feedback, glad I was helpful.