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