Is it really necessary to change the language from the default programming language (English)? I do not think so. My knowledge of English isn't really great, but as soon as I switch to my native language (German), I actually have difficulties with the blocks and their sometimes bizarre names.
In short, you should familiarize yourself with some basic English terms and basically only use English as the language in the designer. This would also make the work of power users much easier.
But of course this problem should be fixed.