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# sourceLanguage

The input language to translate from.

```
final let sourceLanguage: Locale.Language?
```

## Discussion

If this value is set to `nil`, the session tries to identify the source language automatically.
If it can’t identify the language, it prompts the person to choose the source language to use for the translation.

> Note: This value doesn’t update after translation. To see what source language
> the session uses for a particular translation, check the response ``doc://com.apple.Translation/documentation/Translation/TranslationSession/Response/sourceLanguage``.

---

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