a teenage mother is sitting on the couch with her child.
A teenager sits on the couch.
The teenager who is a mother is sitting on the couch.
exists e1 x1 x2 x3 x4.(n_child(x4) & of(x4,x3) & n_female(x3) & n_couch(x3) & with(e1,x4) & on(e1,x3) & Actor(e1,x1) & v_sit(e1) & n_mother(x1) & of(x1,x2) & n_teenage(x2))
exists e1 x1 x2.(n_couch(x2) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_teenager(x1))