I should combine you should combine he should combine we should combine you should combine they should combine
V-ing form
I should be combining you should be combining he should be combining we should be combining you should be combining they should be combining
Perfect
I should have combined you should have combined he should have combined we should have combined you should have combined they should have combined
V-ing perfect
I should have been combining you should have been combining he should have been combining we should have been combining you should have been combining they should have been combining
Negation
Simple form
I should not combine you should not combine he should not combine we should not combine you should not combine they should not combine
V-ing form
I should not be combining you should not be combining he should not be combining we should not be combining you should not be combining they should not be combining
Perfect
I should not have combined you should not have combined he should not have combined we should not have combined you should not have combined they should not have combined
V-ing perfect
I should not have been combining you should not have been combining he should not have been combining we should not have been combining you should not have been combining they should not 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
should I not combine? should you not combine? should he not combine? should we not combine? should you not combine? should they not combine?
V-ing form
should I not be combining? should you not be combining? should he not be combining? should we not be combining? should you not be combining? should they not be combining?
Perfect
should I not have combined? should you not have combined? should he not have combined? should we not have combined? should you not have combined? should they not have combined?
V-ing perfect
should I not have been combining? should you not have been combining? should he not have been combining? should we not have been combining? should you not have been combining? should they not have been combining?