I should concentrate you should concentrate she should concentrate we should concentrate you should concentrate they should concentrate
V-ing form
I should be concentrating you should be concentrating she should be concentrating we should be concentrating you should be concentrating they should be concentrating
Perfect
I should have concentrated you should have concentrated she should have concentrated we should have concentrated you should have concentrated they should have concentrated
V-ing perfect
I should have been concentrating you should have been concentrating she should have been concentrating we should have been concentrating you should have been concentrating they should have been concentrating
Negation
Simple form
I should not concentrate you should not concentrate she should not concentrate we should not concentrate you should not concentrate they should not concentrate
V-ing form
I should not be concentrating you should not be concentrating she should not be concentrating we should not be concentrating you should not be concentrating they should not be concentrating
Perfect
I should not have concentrated you should not have concentrated she should not have concentrated we should not have concentrated you should not have concentrated they should not have concentrated
V-ing perfect
I should not have been concentrating you should not have been concentrating she should not have been concentrating we should not have been concentrating you should not have been concentrating they should not have been concentrating
Interrogative form
Simple form
should I concentrate? should you concentrate? should she concentrate? should we concentrate? should you concentrate? should they concentrate?
V-ing form
should I be concentrating? should you be concentrating? should she be concentrating? should we be concentrating? should you be concentrating? should they be concentrating?
Perfect
should I have concentrated? should you have concentrated? should she have concentrated? should we have concentrated? should you have concentrated? should they have concentrated?
V-ing perfect
should I have been concentrating? should you have been concentrating? should she have been concentrating? should we have been concentrating? should you have been concentrating? should they have been concentrating?
Interro-negative form
Simple form
should I not concentrate? should you not concentrate? should she not concentrate? should we not concentrate? should you not concentrate? should they not concentrate?
V-ing form
should I not be concentrating? should you not be concentrating? should she not be concentrating? should we not be concentrating? should you not be concentrating? should they not be concentrating?
Perfect
should I not have concentrated? should you not have concentrated? should she not have concentrated? should we not have concentrated? should you not have concentrated? should they not have concentrated?
V-ing perfect
should I not have been concentrating? should you not have been concentrating? should she not have been concentrating? should we not have been concentrating? should you not have been concentrating? should they not have been concentrating?