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