A man is mortaring bricks.
A construction worker.
Mortaring bricks is something a construction worker does often.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_mortar(e1) & n_brick(x2) & n_man(x1))
exists x1 x2.(a_topic(x1) & n_worker(x1) & of(x1,x2) & n_construction(x2))