A person is windsurfing in the water.
A person is windsurfing on the street
Windsurfing typically takes place in the water, not on a street.
exists e1 x1 x2.(n_water(x2) & in(e1,x2) & Actor(e1,x1) & v_windsurf(e1) & n_person(x1))
exists e1 x1 x2.(n_street(x2) & on(e1,x2) & Actor(e1,x1) & v_windsurf(e1) & n_person(x1))