People in a courtyard plaza are sitting and standing.
one person is sitting alone at home
People refers to more than one person.  A courtyard plaza is a public place and would not be found at home.
exists e2 e1 x1 x2 x3 x4 x5 x6.(Actor(e2,x4) & v_stand(e2) & in(x4,x5) & n_plaza(x5) & of(x5,x6) & n_courtyard(x6) & n_people(x4) & Actor(e1,x1) & v_sit(e1) & in(x1,x2) & n_plaza(x2) & of(x2,x3) & n_courtyard(x3) & n_people(x1))
exists e1 p1 x1 x2.(at(e1,x2) & n_home(x2) & exists s1.(Theme(s1,x1) & a_alone(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_sit(e1) & n_person(x1) & card_eq_1(x1))