Our super's Ryszard and I typically call him "Panie Ryszku!" whenever we see each other. Oh yes, forgot to mention we've got a Polish maintenance man now, fair English, yet speaks with yours truly solely in Polish.....except of course if my wife's present:-)
It does, if I met a guy named Michał or Patryk Ryszard I'd not think much of it, Paulina Ryszard sounds more like a contrast but I'd automatically know it's a surname and not a middle name.
I think only a few male given names and/or diminutives ending in -EK are also used as surnames, such as Bartek (diminutive of given names Bartłomiej and/or Bartosz) and Marek (given name)
When on the phone, I can sometimes hear others address him the same way. It may simply be a question of correctness vs. colloquial usage, that is to say "incorrect", if slangy, conversation.
European workmen on the whole, have a better education/schooling than their US counterparts in my experience. I don't know this guy except as a super, but perhaps in Poland he was an engineer and was forced to work in the States as building handyman.
If nominative singular is Rysiek, then are the other declensions (singular and plural) stemmed from Ryśk-? Is nominative & vocative plural Ryśkowie? Are the singular genitive & accusative Ryśka and plural genitive & accusative Ryśków? Is dative singular Ryśkowi and dative plural Ryśkom? Is instrumental singular Ryśkiem and instrumental plural Ryśkami? Is locative & vocative singular Ryśku and locative plural Ryśkach?
All three are acceptable. 'Rysiek' is technically a nominative, but it is often used in the role of a vocative. 'Ryśku' is the true vocative of 'Rysiek'', but indeed is rarely heard.
'Rysiu' is technically a vocative of 'Ryś'. It is used as the vocative of the name 'Rysiek' even though its proper vocative would be 'Ryśku'. On the other hand, 'Ryśku' is likely to be heard in conjunction with 'panie': 'panie Ryśku' rather than 'panie Rysiu'.
You may add 'Rychu' to the list which vocative is mostly used between male friends or colleauges among the working class.
@NieNazwany. To me all your declensions look correct.
I switched to Richard when I was naturalized. From that day forward, the only form I and everybody else used was Rich. That's it. Just one word for all occasions and the earth is still spinning in the same direction.