Currently the HA dashboards can be set to only one system wide language. Only the companion app can be set to different languages, but that doesn’t affect the dashboards. I have multiple users in my house, some prefer the English dashboards, while others prefer another language (in my case Dutch). I’m not a programmer so hopefully someone will pickup this request to make it possible to set a dashboard language per device, so that smartphone 1 shows for example the English dashboard and smartphone 2 the Dutch, German, French, etc variant.