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