A dog jumps off the stairs.
A dog is playing on a staircase.
A dog could be jumping of the stairs in order to attack an intruder, which is not the same as playing.
exists e1 s1 x1 x2.(n_stair(x2) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_jump(e1) & n_dog(x1))
exists e1 x1 x2.(on(e1,x2) & n_staircase(x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1))