A woman is sitting on the sidewalk, sketching an image with chalk.
a lady plays with chalk on the ground
Sitting on the sidewalk refers to ground.
exists e1 e2 x1 x2 x3 x4.(n_sidewalk(x2) & for(e1,e2) & with(e2,x4) & n_chalk(x4) & Theme(e2,x3) & Actor(e2,x1) & v_sketch(e2) & n_image(x3) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_woman(x1))
exists e1 x1 x2 x3.(n_ground(x3) & on(e1,x3) & with(e1,x2) & n_chalk(x2) & Actor(e1,x1) & v_play(e1) & n_lady(x1))