Now I found a work-around, which works in text console, KDE Plasma desktop and Konsole. Compared with my last setup, the variable $LC_MESSAGES is important. LC_MESSAGES=C means that message translations should not be searched in translation files. As the result the original English messages are used. $HOME/.config/plasma-localerc: [Formats] LANG=en_US.utf8 LC_MESSAGES=C $HOME/.config/KDE/Sonnet.conf: [General] autodetectLanguage=false backgroundCheckerEnabled=true checkUppercase=true checkerEnabledByDefault=false defaultClient= defaultLanguage=en_US ignore_de= ignore_de_DE= preferredLanguages=en_US, de_DE skipRunTogether=true $HOME/.i18n export LC_MESSAGES=C /etc/sysconfig/language: INPUT_METHOD="" RC_LANG="en_US.utf8" RC_LC_ALL="" RC_LC_MESSAGES="" RC_LC_CTYPE="" RC_LC_COLLATE="" RC_LC_TIME="" RC_LC_NUMERIC="" RC_LC_MONETARY="" RC_LC_PAPER="" ROOT_USES_LANG="ctype" AUTO_DETECT_UTF8="no" INSTALLED_LANGUAGES="de_DE,en_US" Greetings, Björn