Construction workers are working underground.
Construction workers are playing at the playground.
It is unlikely a playground would be underground
exists e1 s1 x1 x2.(a_underground(s1) & Manner(e1,s1) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2 x3.(n_playground(x3) & at(e1,x3) & Actor(e1,x1) & v_play(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2))