English verb conjugation
SHOULD ASCERTAIN

Regular verb: ascertain - ascertained - ascertained

Affirmation

Simple form	V-ing form
I'd ascertain you'd ascertain he'd ascertain we'd ascertain you'd ascertain they'd ascertain	I'd be ascertaining you'd be ascertaining he'd be ascertaining we'd be ascertaining you'd be ascertaining they'd be ascertaining
Perfect	V-ing perfect
I should've ascertained you should've ascertained he should've ascertained we should've ascertained you should've ascertained they should've ascertained	I should've been ascertaining you should've been ascertaining he should've been ascertaining we should've been ascertaining you should've been ascertaining they should've been ascertaining

Negation

Simple form	V-ing form
I shouldn't ascertain you shouldn't ascertain he shouldn't ascertain we shouldn't ascertain you shouldn't ascertain they shouldn't ascertain	I shouldn't be ascertaining you shouldn't be ascertaining he shouldn't be ascertaining we shouldn't be ascertaining you shouldn't be ascertaining they shouldn't be ascertaining
Perfect	V-ing perfect
I shouldn't have ascertained you shouldn't have ascertained he shouldn't have ascertained we shouldn't have ascertained you shouldn't have ascertained they shouldn't have ascertained	I shouldn't have been ascertaining you shouldn't have been ascertaining he shouldn't have been ascertaining we shouldn't have been ascertaining you shouldn't have been ascertaining they shouldn't have been ascertaining

Interrogative form

Simple form	V-ing form
should I ascertain? should you ascertain? should he ascertain? should we ascertain? should you ascertain? should they ascertain?	should I be ascertaining? should you be ascertaining? should he be ascertaining? should we be ascertaining? should you be ascertaining? should they be ascertaining?
Perfect	V-ing perfect
should I have ascertained? should you have ascertained? should he have ascertained? should we have ascertained? should you have ascertained? should they have ascertained?	should I have been ascertaining? should you have been ascertaining? should he have been ascertaining? should we have been ascertaining? should you have been ascertaining? should they have been ascertaining?

Interro-negative form

Simple form	V-ing form
shouldn't I ascertain? shouldn't you ascertain? shouldn't he ascertain? shouldn't we ascertain? shouldn't you ascertain? shouldn't they ascertain?	shouldn't I be ascertaining? shouldn't you be ascertaining? shouldn't he be ascertaining? shouldn't we be ascertaining? shouldn't you be ascertaining? shouldn't they be ascertaining?
Perfect	V-ing perfect
shouldn't I have ascertained? shouldn't you have ascertained? shouldn't he have ascertained? shouldn't we have ascertained? shouldn't you have ascertained? shouldn't they have ascertained?	shouldn't I have been ascertaining? shouldn't you have been ascertaining? shouldn't he have been ascertaining? shouldn't we have been ascertaining? shouldn't you have been ascertaining? shouldn't they have been ascertaining?