system-config-language

system-config-language is a graphical user interface that allows the user to change the default language of the system.  |  https://fedorahosted.org/system-config-language/
If you are using Wayland on Fedora then you need to run following first xhost +si:localuser:root this will allow to run applications requiring root access. See https://bugzilla.redhat.com/show_bug.cgi?id=1274451