I'd be excusing you'd be excusing he'd be excusing we'd be excusing you'd be excusing they'd be excusing
Perfect
I should've excused you should've excused he should've excused we should've excused you should've excused they should've excused
V-ing perfect
I should've been excusing you should've been excusing he should've been excusing we should've been excusing you should've been excusing they should've been excusing
Negation
Simple form
I shouldn't excuse you shouldn't excuse he shouldn't excuse we shouldn't excuse you shouldn't excuse they shouldn't excuse
V-ing form
I shouldn't be excusing you shouldn't be excusing he shouldn't be excusing we shouldn't be excusing you shouldn't be excusing they shouldn't be excusing
Perfect
I shouldn't have excused you shouldn't have excused he shouldn't have excused we shouldn't have excused you shouldn't have excused they shouldn't have excused
V-ing perfect
I shouldn't have been excusing you shouldn't have been excusing he shouldn't have been excusing we shouldn't have been excusing you shouldn't have been excusing they shouldn't have been excusing
Interrogative form
Simple form
should I excuse? should you excuse? should he excuse? should we excuse? should you excuse? should they excuse?
V-ing form
should I be excusing? should you be excusing? should he be excusing? should we be excusing? should you be excusing? should they be excusing?
Perfect
should I have excused? should you have excused? should he have excused? should we have excused? should you have excused? should they have excused?
V-ing perfect
should I have been excusing? should you have been excusing? should he have been excusing? should we have been excusing? should you have been excusing? should they have been excusing?
Interro-negative form
Simple form
shouldn't I excuse? shouldn't you excuse? shouldn't he excuse? shouldn't we excuse? shouldn't you excuse? shouldn't they excuse?
V-ing form
shouldn't I be excusing? shouldn't you be excusing? shouldn't he be excusing? shouldn't we be excusing? shouldn't you be excusing? shouldn't they be excusing?
Perfect
shouldn't I have excused? shouldn't you have excused? shouldn't he have excused? shouldn't we have excused? shouldn't you have excused? shouldn't they have excused?
V-ing perfect
shouldn't I have been excusing? shouldn't you have been excusing? shouldn't he have been excusing? shouldn't we have been excusing? shouldn't you have been excusing? shouldn't they have been excusing?