Welcome to Seamly! Unfortunately, many of the translations are incomplete. We would love for you to help fix that! The best way is by using QT Linquist & the git repository. @Douglas can provide guidance on using those if you don’t know how, or don’t have a local source of information to guide you.
The translations are incomplete, which varies from language to language. This is do to several reasons. Since forking from Valentina the app has undergone many changes in the UI which means the translations also need updating.
As @Pneumarian has pointed out the preferred method of translating the apps and measurements (which BTW we just made a lot easier by consolidating the measuremts to a single file per language) is to use Qt’s Linguist app.
I should note that I would hold off for a week or so attempting any translating the current ui as I’m finishing up a redesign of the dialogs and Properties Editor that will make further text changes to the ui.