R often comes in a wonderful mix of languages, as seen in the screenshot:
The simplest way to change that:
Sys.setenv(LANG = “de”)
Then the R session will be in German. But only for this one session! If you want to change the language permanently, you can specify a preference in the .Renviron file (the file must be created if it doesn’t already exist). To do this, open the terminal and type:
vi .Renviron
Type, press “i” to enter Insert mode, and then
LANG=“de”
enter the following. Then press ESC and type “:wq!” (without quotes). Restart R, and it will remain in German.