some of the people in the crowd are having a drink
People are drinking.
people are having a drink is same as people are drinking
exists e1 x1 x2 x3 x4.(n_crowd(x3) & n_people(x2) & Theme(e1,x4) & Actor(e1,x1) & v_have(e1) & n_drink(x4) & of(x1,x2) & in(x2,x3) & n_thing(x1))
exists e1 x1.(Actor(e1,x1) & v_drink(e1) & n_people(x1))