I'd be assisting you'd be assisting she'd be assisting we'd be assisting you'd be assisting they'd be assisting
Perfect
I should've assisted you should've assisted she 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 she 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 she 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 she 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 she 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 she 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 she assist? should we assist? should you assist? should they assist?
V-ing form
should I be assisting? should you be assisting? should she be assisting? should we be assisting? should you be assisting? should they be assisting?
Perfect
should I have assisted? should you have assisted? should she 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 she 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 she 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 she 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 she 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 she have been assisting? shouldn't we have been assisting? shouldn't you have been assisting? shouldn't they have been assisting?