A dog plays on the beach.
A dog is playing fetch on the beach.
Just because a dog plays on the beach does not mean it is playing fetch. It could be digging up buried treasurers.
exists e1 x1 x2.(n_beach(x2) & on(e1,x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1))
exists e1 s1 x1 x2.(n_beach(x2) & on(e1,x2) & a_fetch(s1) & Manner(e1,s1) & Actor(e1,x1) & v_play(e1) & n_dog(x1))