Two boys playing in the sand.
Two boys are making a moat at the beach.
The boys could be doing other things in the sand, such as building a sandcastle. They also could be playing in a sandbox or anywhere sand is present, not just at the beach.
exists e1 x1 x2 x3.(n_sand(x3) & a_topic(x1) & in(e1,x3) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_boy(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(n_beach(x3) & at(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_make(e1) & n_moat(x2) & n_boy(x1) & card_eq_2(x1))