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