We generally use “quit” to mean “quit/exit the app”. That’s interchangeable with alt+f4 for single-window apps, but not for multi-window ones.
Those are already taken:
super+m: open the calendar drop-down (“messages”)
super+n: expands and focuses the currently displayed notification
There was an initiative to make all (most) system shortcuts super-based, but that was pretty much completed years and ago.
Do you have an concrete suggestions for shortcuts that don’t exist yet, or ones that you’d like to see changed (although changing existing shortcuts always bears some risk of alienating existing users)?
Most shortcuts are already based on english words. Ctrl+R to refresh, Ctrl+C to copy, Ctrl+Q to quit, Ctrl+T to open a new tab, Ctrl+P to print, Ctrl+O to Open, ctrl+S to save etc.
Mnemonics otoh are translated - but these aren’t mnemonics.
I’ve been using Super+W for closign windows - it’s super convenient given my keyboard doesn’t have persistent F keys, but also I’ve also definitely triggered it by accident far more often than alt+fn+f4.
I believe that, like the Ctrl, Alt, Shift, Enter keys, there are no translations and English is already in demand as a very widespread language. I believe it could be based on English, as those who have contact with technology inevitably also have contact with this language.