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