I'd be filtering you'd be filtering she'd be filtering we'd be filtering you'd be filtering they'd be filtering
Perfect
I should've filtered you should've filtered she should've filtered we should've filtered you should've filtered they should've filtered
V-ing perfect
I should've been filtering you should've been filtering she should've been filtering we should've been filtering you should've been filtering they should've been filtering
Negation
Simple form
I shouldn't filter you shouldn't filter she shouldn't filter we shouldn't filter you shouldn't filter they shouldn't filter
V-ing form
I shouldn't be filtering you shouldn't be filtering she shouldn't be filtering we shouldn't be filtering you shouldn't be filtering they shouldn't be filtering
Perfect
I shouldn't have filtered you shouldn't have filtered she shouldn't have filtered we shouldn't have filtered you shouldn't have filtered they shouldn't have filtered
V-ing perfect
I shouldn't have been filtering you shouldn't have been filtering she shouldn't have been filtering we shouldn't have been filtering you shouldn't have been filtering they shouldn't have been filtering
Interrogative form
Simple form
should I filter? should you filter? should she filter? should we filter? should you filter? should they filter?
V-ing form
should I be filtering? should you be filtering? should she be filtering? should we be filtering? should you be filtering? should they be filtering?
Perfect
should I have filtered? should you have filtered? should she have filtered? should we have filtered? should you have filtered? should they have filtered?
V-ing perfect
should I have been filtering? should you have been filtering? should she have been filtering? should we have been filtering? should you have been filtering? should they have been filtering?
Interro-negative form
Simple form
shouldn't I filter? shouldn't you filter? shouldn't she filter? shouldn't we filter? shouldn't you filter? shouldn't they filter?
V-ing form
shouldn't I be filtering? shouldn't you be filtering? shouldn't she be filtering? shouldn't we be filtering? shouldn't you be filtering? shouldn't they be filtering?
Perfect
shouldn't I have filtered? shouldn't you have filtered? shouldn't she have filtered? shouldn't we have filtered? shouldn't you have filtered? shouldn't they have filtered?
V-ing perfect
shouldn't I have been filtering? shouldn't you have been filtering? shouldn't she have been filtering? shouldn't we have been filtering? shouldn't you have been filtering? shouldn't they have been filtering?