We'll create fresh WordPress site with R3DF Dashboard Language Switcher installed. You have 20 minutes to test the plugin after that site we'll be deleted.
This plugin allows logged in users to select the language they would like to use when viewing the WordPress dashboard. It works with multisite and single site installs of WordPress.
To add languages to WordPress ( since 4.1 ), simply select a new language from the ones available on the “Site Language” setting on the “General Settings” page.
When you save your settings, the new language will be added to the site. (and selected as the current language)
It is up to plugin and theme authors to provide translations for their works. If you change the site language, and a plugin or theme is not translated (usually still showing English),
you need to contact the authors of those works to get the needed translation files.
There is a French translation of this plugin included. It was mostly a test of the translation of the plugin. It’s not a great translation, if you can improve it please let me know.