Pedestrians on a city street all stand by the curb staring off.
people standing by the curb waiting for a bus
The people standing on the curb may not be waiting for a bus at all.
exists e1 s1 x1 x2 x3 x4 x5 x6.(n_curb(x5) & a_topic(x1) & on(x1,x2) & by(x2,x5) & a_off(s1) & Manner(e1,s1) & Actor(e1,x6) & v_stare(e1) & (x5 = x6) & n_stand(x2) & of(x2,x4) & n_street(x4) & of(x2,x3) & n_city(x3) & n_pedestrian(x1))
exists e1 e2 x1 x2 x3 x4.(n_curb(x3) & a_topic(x1) & for(e1,e2) & for(e2,x4) & n_bus(x4) & Actor(e2,x2) & v_wait(e2) & by(e1,x3) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_people(x1))