Kids sit on a ledge and talk.
A couple of kids sit on a ledge and talk about romance
Just because kids talk doesn't imply that there are a couple of kids. All kids are not talking about romance.
exists e1 x1 x2 x3 x4.(on(e1,x2) & n_talk(x4) & n_ledge(x3) & subset_of(x4,x2) & subset_of(x3,x2) & Actor(e1,x1) & v_sit(e1) & n_kid(x1))
exists e1 x1 x2 x3 x4 x5 x6.(on(e1,x3) & subset_of(x5,x3) & about(x5,x6) & n_romance(x6) & n_talk(x5) & subset_of(x4,x3) & n_ledge(x4) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_kid(x2) & n_couple(x1))