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