a small black and white dog running on the beach with several people in the background
Dogs are running in and out of the surf while people throw them sticks.
Dogs is more than one dog.  Just because a dog is running on the beach with people in the background it does not mean the people throw them sticks.
exists e1 s1 s2 s3 s4 x1 x2 x3 x4 x5.(n_background(x5) & n_beach(x3) & a_topic(x1) & in(e1,x5) & with(e1,x4) & n_people(x4) & a_several(s4) & Theme(s4,x4) & on(e1,x3) & Actor(e1,x2) & v_run(e1) & (x1 = x2) & n_dog(x1) & a_white(s3) & Theme(s3,x1) & a_black(s2) & Theme(s2,x1) & a_small(s1) & Theme(s1,x1))
exists e2 e1 p1 p2 s1 x1 x2 x3 x6.(n_thing(x6) & n_surf(x3) & n_thing(x3) & exists e5 p4 x5.(exists e6.(Actor(e6,x6) & v_stick(e6)) & Topic(e5,p4) & Actor(e5,x5) & v_throw(e5) & n_people(x5)) & while(e2,p2) & of(e2,x3) & r_out(e2) & Actor(e2,x2) & v_run(e2) & n_dog(x2) & exists e3 p3 x4.(exists e4.(Actor(e4,x3) & v_stick(e4)) & Topic(e3,p3) & Actor(e3,x4) & v_throw(e3) & n_people(x4)) & while(e1,p1) & a_in(s1) & Manner(e1,s1) & Actor(e1,x1) & v_run(e1) & n_dog(x1))