A group of teenagers are sitting together on the grass.
The teenagers are studying for a test on the grass.
just because teenagers are sitting together on grass that  doesn't mean they are studying for test
exists e1 p1 x1 x2 x3.(n_grass(x3) & on(e1,x3) & exists s1.(Theme(s1,x1) & a_together(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_teenager(x2) & n_group(x1))
exists e1 x1 x2 x3.(n_grass(x3) & n_teenager(x1) & for(e1,x2) & on(x2,x3) & n_test(x2) & Actor(e1,x1) & v_study(e1))