More or less the difference between "I just have a minute" versus "I only have a minute", so not much.
The only sentence i saw thus far on DL with appena was when it meant 'As soon as'
Appena mio padre arriva, mangiamo - We eat as soon as my father arrives
"Soltanto se mio padre arriva mangiamo" . Si mangia solo nel caso in cui dovesse arrivare il padre (caso incerto).
What if I change the word "se" for "quando" in your sentence, franceskoo? What will the difference between "Apenna mio padre arriva, mangiamo" and "Soltanto quando mio padre arriva, mangiamo"?
If you ask me to guess, I'd say the difference is that the former implies they'll eat immediately after the father's arrival, and the latter simply means they won't eat until the father does arrive.
Appena is "a pena" = with pain, barely, as soon as; soltanto is "solo + tanto = only + so much; proprio = just exactly as I think. More or less the similarities among just, only, barely, hardly.
i neither have a pen or a.pencil...all are broken duevto the stress of figuring out what theyre saying..good luck to all.
Italian is very idiomatic so you have to use a different mindset. You gotta think outside the box. Like a child.
In English we often use the phrase "i have a moment" in the same manner as "a minute."