A black dog walking in dirt has a soccer ball in his mouth.
Someone is playing fetch with the dog.
Fetch is usually played with an object that fits in a dog's mouth, something smaller or flatter than a soccer ball. A soccer ball probably won't fit in a dog's mouth.
exists e1 s1 x1 x2 x3 x4 x5 x6.(Theme(e1,x4) & Actor(e1,x1) & v_have(e1) & in(x4,x6) & n_mouth(x6) & of(x6,x1) & n_male(x1) & n_ball(x4) & of(x4,x5) & n_soccer(x5) & in(x1,x3) & n_dirt(x3) & n_walking(x1) & of(x1,x2) & n_dog(x2) & a_black(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(n_dog(x3) & with(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_fetch(x2) & n_person(x1))