Thanks for doing further research (a valuable resource) and for the advice about the problem with alternatives - some of which I know.
I have only ever heard of Prugna (never heard Susina) so it could well be a different variety eg Damson as you say. (PS a Latin web search reveals “Japanese plum” !)
But in my (many) dictionaries, it only ever gives prugna for plum but it does give plum for susina.
I’m still waiting to be made a Contributor, I did email @lien.
Interestingly (aka annoyingly) I have just been asked to type the Italian for plum and answered la prugna and got it wrong! (Because there are two entries for Plum.)
Hi @sandslane, what do you think about this entry?:
aspro = sour
Alternative (more common?) words are: acido, acro and agro. (Also acerbo and stizzozo.)
CORRECTION - Use ACRE
According to Linguee aspro is bitter, harsh and occasionally sour/rugged/tart and used not just for food. Acro should be acre - bitter/acrid/pungent/harsh/biting.
I found a quite a few aspro references to tart taste and some to sour taste (along with acre/agro and less common acido the latter more referred to as the obvious acidic.
All in all I think aspro for sour/tart is quite good looking at the evidence of usage. Personally I would keep it and have the others as alternatives.
I suppose there are lots of words both English and Italian with very slight differences.
I found the following on treccani - really interesting.
http://www.treccani.it/magazine/lingua_italiana/domande_e_risposte/lessico/lessico_186.html
and this too supporting aspro
I’ve just realised why I didn’t recognise any of the Italain words for sour because I have only ever used:
Amaro = Bitter (which of course is not the same).
Not sure what I think of this Anglicised Italian (or do I mean Italian-ised Eglish?).
il rosbif = roast beef
It’s probably a modern thing.
What about l’arrosto di manzo? (or even il roast beef)
Hi @sandslane - @lien has kindly made me a contributor to the Food & Drink course so I’ll add some features to it over the next few days.
Would you like to be a contributor too - as you are with the other ones?
that would be good
Hi @sandslane, I’ve made you a Contributor.
I’ve amended Prune and Plum as discussed.
When I created a new entry for La Susina - it actually came up as an available choice as La susina selvatica = Damson - which proves the point.
I couldn’t find rosbif in linguee examples the other two were used though. It is used in French and Spanish. Maybe it is a mistake.
Thanks for looking.
I’ll try to asks a couple of Italians.
Otherwise, how about “l’arrosto di manzo” with “il roast beef” as a visible alternative?
Sounds good to me. Are you putting hidden alternatives without the articles? I’ve done that with the other RoyGBiv courses.
No I’ve hardly started making amendments - only added the “what next?” and “Reversed levels”, altered the descriptions and tags and made a couple of corrections.
I’ve learned to always use the definitive article and it does help with the gender, but please feel free to do that if you care to.
What do you think of "non gassato" and "non frizzante" as a visible alternative to
liscio = still, non-carbonated
PS - DONE
PS - THIS IS ALREADY AN ALTERNATIVE frizizante added to
gassato = fizzy, sparkling, carbonated
I always use the article when I can. Some courses don’t put it or even do some with and some without which makes things really difficult. I just add it as an alternative thinking of other users especially as the ‘the’ is not recorded in the English version and so other users might not add it. If i’m contributing to a course where thecreator doesn’t use it I then put it with the article as an alternative. At least then you don’t have to think do I add it or not.
They sound ok. I have also found acqua naturale for still water although it is often translated as mineral water.
I think I’d say “acqua minerale non gassosa” if I wanted still spring/ mineral water but I see “acqua minerale naturale” is popular.
I’ve never come across non gassosa. In linguee for still mineral water it’s acqua minerale/naturale or even acqua minerale piatta. From a forum in wordreference an Italian says for the two types 'You have to ask for “acqua (minerale) liscia/ naturale” or “acqua (minerale) gassata/ frizzante”.
It might be “non gassata” but that may be something we used as children - perhaps not knowing the correct phrase! 
hi i think corrupt would be better as corrotto rather than vizioso in this course
vizioso - seems to be vicious/depraved/immoral/defective