People stand along the sidewalk watching a bus come their way.
People at a bus station are waiting to board.
People watching a bus come their way are not necessarily waiting to board.
exists e2 e1 e3 x1 x2 x3 x4 x5 x6.(n_way(x6) & of(x6,x2) & n_thing(x2) & n_sidewalk(x2) & along(e1,x2) & Theme(e3,x4) & Actor(e3,x3) & v_watch(e3) & Theme(e2,x6) & Actor(e2,x5) & v_come(e2) & (x4 = x5) & n_bus(x4) & (x2 = x3) & Actor(e1,x1) & v_stand(e1) & n_people(x1))
exists e1 x1 x2 x3 x4.(to(e1,x4) & n_board(x4) & Actor(e1,x1) & v_wait(e1) & at(x1,x2) & n_station(x2) & of(x2,x3) & n_bus(x3) & n_people(x1))