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