yes only has an apostrophe for OWNERSHIP, and CONTRATION (It is = it's).
plurals DON'T take a apostrophe.
if its plural AND ownership....eg.
the house belongs to MORE than one lady...
the ladies' house...
yes it does look funny, ending a word with an apostrophe but its right.
something totally random but if you're game....
in your example...it is okay to say Regina loves to play sport's after class....
the question is...sport's what?
Regina loves to play John's after class..
john's what? john's computer.
Regina loves to play john's computer after class