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