Documentation Level: 
Introduction
Documentation Status: 
No known problems
Multilingual support is provided by the Locale core module.
Add a language
- Enable the Locale module
- 
        Go to the language configuration page: Configuration > Regional and language > Languages
 (admin/config/regional/language)
- 
        On that page:
- Add the languages you want
- 
                Set a default language.
 Never change the default language, otherwise things will break!
 
- Continue with the Automatic or Manual method below to update your strings
Update strings (automatic method)
- Install the Localization update (l10n_update) module (optional).
- 
        Update the translations for your languages: Configuration > Regional and language > Translate Interface > Update
 (admin/config/regional/translate/update)
Update strings (manual method)
- Download the translation files you want from translation server.
- 
        Upload the translation files to your site: Configuration > Regional and language > Translate Interface > Import
 (admin/config/regional/translate/import)
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