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