Quite often I have the need to start an application in a foreign language. Given that the language is installed for that program all you have to do is via a terminal:
LANG=en_US firefox
For KDE you have to use a slightly different syntax:
KDE_LANG=en_US kwrite
Since these things are entered in a terminal they are forgotten after you’ve closed the terminal.
As a last note: using this way the only application affected by the new LANG is the application started in the same command line. The rest of the session will not be affected!
