The second version may occur as a protest against someone who claims that only some S's are not P's, when really none of them are. Some pigs are wild animals. All elderly members of the Dragon club are inveterate prattlers. No canaries are melancholy creatures. Some holidays spent in the mountains are not stimulating and refreshing vacations.
Some professors are terrible bores.
It is easy to make mistakes on these. B. Change the quality but not the quantity. No coins are square objects. Some professors are terrible bores. All hogs are porcine creatures.