Region & Language
This module sets your preferred languages and formats for the desktop and applications.
In most cases, you can simply select the language and all the options are set accordingly. The desktop and its applications are written in American English and translated into many languages by teams of volunteers. These translations need to be installed before you can use them.
[!NOTE] Make sure you've installed the language packages or translations for the languages you want. Since the desktop is built on the Qt libraries, you also need Qt's translations for a fully translated interface.
Each entry shows an example of what its setting looks like. As well as numbers, you can see how currency values, dates and times are displayed. When you change a setting, you see the effect before you apply it.
Languages
Modify… on the language entry shows your languages. Add More… lists the available languages and shows your selected one first. If it shows “No Language Configured”, you're using the language set by the system. If the language you want isn't listed, install it using the usual method for your system. Add languages in the order you want to see them in your applications.
You can remove a language by selecting it and clicking the remove button, and change the order of preference with the buttons next to it.
Formats
If you need different individual settings, select a locale for Numbers, Time, Currency, Measurements, Paper Size, Address, Name or Phone number.
Data and Storage Sizes chooses how sizes are shown: Binary in kibibytes (KiB), mebibytes (MiB) and gibibytes (GiB), the older Binary in kilobytes (KB), megabytes (MB) and gigabytes (GB), or Decimal in kilobytes (kB), megabytes (MB) and gigabytes (GB).
Changing a language automatically changes the settings for numbers, currency and so on to the matching country or region. The configuration file is ~/.config/plasma-localerc.
Changes take effect the next time you log in. On some systems the module first generates the locale files it needs, and tells you when that's finished.