I'd be stiffering you'd be stiffering she'd be stiffering we'd be stiffering you'd be stiffering they'd be stiffering
Perfect
I should've stiffered you should've stiffered she should've stiffered we should've stiffered you should've stiffered they should've stiffered
V-ing perfect
I should've been stiffering you should've been stiffering she should've been stiffering we should've been stiffering you should've been stiffering they should've been stiffering
Negation
Simple form
I shouldn't stiffer you shouldn't stiffer she shouldn't stiffer we shouldn't stiffer you shouldn't stiffer they shouldn't stiffer
V-ing form
I shouldn't be stiffering you shouldn't be stiffering she shouldn't be stiffering we shouldn't be stiffering you shouldn't be stiffering they shouldn't be stiffering
Perfect
I shouldn't have stiffered you shouldn't have stiffered she shouldn't have stiffered we shouldn't have stiffered you shouldn't have stiffered they shouldn't have stiffered
V-ing perfect
I shouldn't have been stiffering you shouldn't have been stiffering she shouldn't have been stiffering we shouldn't have been stiffering you shouldn't have been stiffering they shouldn't have been stiffering
Interrogative form
Simple form
should I stiffer? should you stiffer? should she stiffer? should we stiffer? should you stiffer? should they stiffer?
V-ing form
should I be stiffering? should you be stiffering? should she be stiffering? should we be stiffering? should you be stiffering? should they be stiffering?
Perfect
should I have stiffered? should you have stiffered? should she have stiffered? should we have stiffered? should you have stiffered? should they have stiffered?
V-ing perfect
should I have been stiffering? should you have been stiffering? should she have been stiffering? should we have been stiffering? should you have been stiffering? should they have been stiffering?
Interro-negative form
Simple form
shouldn't I stiffer? shouldn't you stiffer? shouldn't she stiffer? shouldn't we stiffer? shouldn't you stiffer? shouldn't they stiffer?
V-ing form
shouldn't I be stiffering? shouldn't you be stiffering? shouldn't she be stiffering? shouldn't we be stiffering? shouldn't you be stiffering? shouldn't they be stiffering?
Perfect
shouldn't I have stiffered? shouldn't you have stiffered? shouldn't she have stiffered? shouldn't we have stiffered? shouldn't you have stiffered? shouldn't they have stiffered?
V-ing perfect
shouldn't I have been stiffering? shouldn't you have been stiffering? shouldn't she have been stiffering? shouldn't we have been stiffering? shouldn't you have been stiffering? shouldn't they have been stiffering?