A person in a green shirt skateboards.
A person rides a skateboard
You ride a skateboard when you skateboard.
exists s1 x1 x2 x3.(a_topic(x1) & in(x1,x2) & n_skateboard(x2) & of(x2,x3) & n_shirt(x3) & a_green(s1) & Theme(s1,x2) & n_person(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_skateboard(x2) & n_person(x1))