A group of young boys are playing football.
Some boys are playing a sport.
" Some" is synonymous with "a group of", and football is a sport.
exists e1 s1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_football(x3) & of(x1,x2) & n_boy(x2) & a_young(s1) & Theme(s1,x2) & n_group(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_sport(x2) & n_boy(x1))