> ## Documentation Index
> Fetch the complete documentation index at: https://docs.inworld.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Language tags

> Speak each part of a text in the language you choose with inline lang tags.

A single text often mixes languages: a language tutor quoting a Spanish word, a travel guide naming a Japanese temple, an assistant reading a French title. Wrap each part of the text in `<lang>` tags that name its language, and each part is spoken in that language, with that language's pronunciation.

```
<lang lang="en-US">In Spanish, the word</lang> <lang lang="es-ES">llama</lang> <lang lang="en-US">means flame.</lang>
```

"In Spanish, the word" and "means flame" are spoken in English, and "llama" in Spanish.

Language tags work with `inworld-tts-2` on every endpoint: [non-streaming](https://docs.inworld.ai/tts/synthesize-speech.md), [streaming](https://docs.inworld.ai/tts/synthesize-speech-streaming.md), [WebSocket](https://docs.inworld.ai/tts/synthesize-speech-websocket.md), [async](https://docs.inworld.ai/tts/synthesize-speech-async.md) and [batch](https://docs.inworld.ai/tts/synthesize-speech-batch.md).

## When to use language tags

Use language tags when you need a specific language spoken in the middle of a sentence, and especially for text that is written the same way in two languages. Without a tag, the model has to guess which reading you mean.

- **Chinese and Japanese** share characters. `日本大学` is *Rìběn dàxué* in Chinese and *Nihon daigaku* in Japanese:
  ```
  <lang lang="zh-CN">这所学校的日语名字是</lang><lang lang="ja-JP">日本大学。</lang>
  ```
- **English and Spanish** share many spellings. `llama` is the animal in English, but in Spanish it means "flame" and is pronounced differently, as in the example above.

## Syntax

- Open a span with `<lang lang="CODE">` and close it with `</lang>`, where `CODE` is a [BCP-47](https://www.rfc-editor.org/info/bcp47) language tag, such as `es`, `es-MX` or `ja-JP`. See [supported languages](https://docs.inworld.ai/tts/capabilities/multilingual.md#supported-languages).
- The SSML spelling `<lang xml:lang="CODE">` is accepted too, so SSML generated by other tools works unchanged.
- Tag and attribute names are **case insensitive**, and the code may use single, double or no quotes.
- Tags do not nest. Close each span before opening the next.
- A `</lang>` with no open span, and a tag whose code is not a valid language tag, are ignored.

## WebSocket

How you send language tags on a [WebSocket](https://docs.inworld.ai/tts/synthesize-speech-websocket.md) context depends on how [the context buffers text](https://docs.inworld.ai/tts/synthesize-speech-websocket.md#choose-how-text-is-buffered):

- **`autoMode: false`**: make each flush self-contained. Wrap every part of the flushed text in the language it should be spoken in, and close every span you open before you flush.
- **`autoMode: true` with `CLIENT_SEGMENTED`**: make each `sendText` payload self-contained in the same way.
- **`autoMode: true` with `SENTENCE_BOUNDARY`**: send text as it arrives, including individual tokens from an LLM. A tag may be split across messages, and a span may continue across several.

<Note>
Tags count toward the characters billed for a request, as other markup does.
</Note>