Two children run along a boardwalk that crosses over a body of water.
Some boys are playing with Legos.
Some boys would normally refer to more than two children.  The children could not be running on the boardwalk while playing with Legos.
exists e1 e2 x1 x2 x3 x4 x5.(along(e1,x2) & over(e2,x4) & of(x4,x5) & n_water(x5) & n_body(x4) & Actor(e2,x3) & v_cross(e2) & (x2 = x3) & n_boardwalk(x2) & Actor(e1,x1) & v_run(e1) & n_child(x1) & card_eq_2(x1))
exists e1 x1 x2.(ne_org_legos(x2) & with(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1))