I'd say hens should also count as chickens... if they were in the farmyard.. though I agree it would be a chicken on the table and at the butcher's or supermarket.
I fail to see your point. Even though all hens are chickens, not all chickens are hens (there are cocks / roosters, too). Certainly you would not translate “oameni” by “teachers” because “teachers should also count as people,” would you?
In singular, plural, demonstrative plural :
copil, copii, copiii
pui, puii, puii
Am I right ?
Which is the more exceptional, the triple or the double 'i' ?