Pls use the pot files in ‘invent/languages’ folder as a template to create .po files.http://www.poedit.net/ -Poedit is the popular free editor for creating .po and the corresponding binary .mo files.
You may need to do an update in POEdit to see all the strings.
translating is no problem, what I mean is the links. i.e.
domainname.de/wordpress/department/gestalttherapeutische-weiterbildungen/
or
domainname.de/wordpress/course/gestalt-beratung/
or
domainname.de/wordpress/faculty/claudia-feller/
If I want the words marked strong in my language, I think that is nothing that can be done by editig the po file.