People play in a fountain at twilight.
People play outside in the water.
Just because people play in a fountain doesn't mean the fountain is filled with water.
exists e1 x1 x2 x3.(at(e1,x3) & n_twilight(x3) & in(e1,x2) & n_fountain(x2) & Actor(e1,x1) & v_play(e1) & n_people(x1))
exists e1 s1 x1 x2.(n_water(x2) & in(e1,x2) & a_outside(s1) & Manner(e1,s1) & Actor(e1,x1) & v_play(e1) & n_people(x1))