How do I set up an AI agent that speaks Spanish or another language and switches languages during a call?

AI agents support many languages on calls and on messaging channels, and an agent can switch languages in the middle of a conversation. Different languages do not cost more: voice is charged per minute by voice provider, not by language, and a call that switches languages is not charged for multiple languages.

1. In the language drop-down in the agent builder (English by default), choose multi-language and select English as well as the other languages you want, for example English and Spanish, or English, Spanish and German.
2. Pick a voice made in the language that matters most. In the voice picker you can see the language each voice was created in and filter by language (for example Spanish) and accent (for example Latin or British). An English (US) voice speaking Spanish sounds like an English speaker trying to speak Spanish. For an agent that moves between English and Spanish, pick a Spanish voice so it can speak both.
3. For one bilingual agent, add an instruction such as: always respond to the customer in the same language they are speaking. The agent keeps going in the language the conversation starts in and follows the caller when they switch, including callers who mix English and Spanish (Spanglish).

Do not select only the other language, even for languages such as Chinese, Vietnamese or Japanese. Callers who speak another language often say names and some words in English, such as the name Mike. If English is not selected, the agent is not listening for English and does nothing when it hears the English word.

To give each language its own voice on the phone, make a second-language copy of the agent and route callers to it:

1. Go to your list of agents, click the three dots on the agent and click Duplicate. Rename the copy, for example Spanish.
2. Open the copy's workflow and open each conversation node. Change it from Static response to AI generated. The AI then treats your English text as instructions instead of saying it word for word and translates the messages for you, so you do not rewrite everything.
3. Save, then add an instruction to the copy's prompt such as: you are required to only speak Spanish to the customer.
4. Choose a voice built for that language.
5. In the English agent's workflow, ask callers in a conversation node whether they want English or Spanish, or tell them to say Spanish at any time to be transferred, and give each answer its own route. Turn on the option to allow telephone key press so they can press 1 for English or 2 for Spanish, or just say it.
6. Add a Forward to agents step on the Spanish route that sends those callers to the Spanish agent.

A static response says exactly the same words every time, while AI generated lets the AI decide what to say. That is why switching to AI generated is the quick way to turn an agent into an agent for any other language.

For text messages you do not need a second agent. Just tell the AI to respond in the customer's language.

To translate a message a caller leaves, use the Ask and save node for the message step in the workflow builder and instruct it, for example: regardless of what language you get the message in, always save it as English (or the language you want).

The AI can also translate your content, such as a website or FAQs. Have a native speaker proofread or approve a translation before putting it into production.