A British guard marches while on duty.
A British guard marches to the beat of the drum while on duty
A British guard could march without the beat of the drum.
(x)
exists e1 s1 s2 x1 x2 x3 x4 x5 x6.(n_drum(x5) & on(e1,x6) & n_duty(x6) & Theme(e1,x2) & Actor(e1,x1) & v_event(e1) & to(x2,x4) & n_while(x4) & of(x4,x5) & a_beat(s2) & Theme(s2,x4) & n_march(x2) & of(x2,x3) & n_guard(x3) & a_british(s1) & Theme(s1,x2) & n_thing(x1))