My whole system is in my preferred language, except Xcode. There's no use Googling "Xcode change language" or even "xcode change language -iphone -IDL -parse -Python -app -localization -internationalization -swift -objective-c", it only turns up developer questions.
How do I change the UI language for Xcode?
Best Answer
As Tom pointed out, XCode is only available in english on the Mac App Store !
If you look on other apps you'll see the available localizations for example on Apple's Number.