a boy runs through the grass.
A child runs on grass.
Running on the grass and through the grass are essentially the same thing.
exists e1 x1 x2.(n_grass(x2) & through(e1,x2) & Actor(e1,x1) & v_run(e1) & n_boy(x1))
exists e1 x1 x2.(on(e1,x2) & n_grass(x2) & Actor(e1,x1) & v_run(e1) & n_child(x1))