should preascertain
Regular verb: preascertain - preascertained- preascertained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd preascertain
you'd preascertain
he'd preascertain
we'd preascertain
you'd preascertain
they'd preascertain 	I'd be preascertaining
you'd be preascertaining
he'd be preascertaining
we'd be preascertaining
you'd be preascertaining
they'd be preascertaining	I should've preascertained
you should've preascertained
he should've preascertained
we should've preascertained
you should've preascertained
they should've preascertained	I should've been preascertaining
you should've been preascertaining
he should've been preascertaining
we should've been preascertaining
you should've been preascertaining
they should've been preascertaining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't preascertain
you shouldn't preascertain
he shouldn't preascertain
we shouldn't preascertain
you shouldn't preascertain
they shouldn't preascertain 	I shouldn't be preascertaining
you shouldn't be preascertaining
he shouldn't be preascertaining
we shouldn't be preascertaining
you shouldn't be preascertaining
they shouldn't be preascertaining	I shouldn't have preascertained
you shouldn't have preascertained
he shouldn't have preascertained
we shouldn't have preascertained
you shouldn't have preascertained
they shouldn't have preascertained	I shouldn't have been preascertaining
you shouldn't have been preascertaining
he shouldn't have been preascertaining
we shouldn't have been preascertaining
you shouldn't have been preascertaining
they shouldn't have been preascertaining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I preascertain?
should you preascertain?
should he preascertain?
should we preascertain?
should you preascertain?
should they preascertain? 	should I be preascertaining?
should you be preascertaining?
should he be preascertaining?
should we be preascertaining?
should you be preascertaining?
should they be preascertaining? 	should I have preascertained?
should you have preascertained?
should he have preascertained?
should we have preascertained?
should you have preascertained?
should they have preascertained? 	should I have been preascertaining?
should you have been preascertaining?
should he have been preascertaining?
should we have been preascertaining?
should you have been preascertaining?
should they have been preascertaining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I preascertain?
shouldn't you preascertain?
shouldn't he preascertain?
shouldn't we preascertain?
shouldn't you preascertain?
shouldn't they preascertain? 	shouldn't I be preascertaining?
shouldn't you be preascertaining?
shouldn't he be preascertaining?
shouldn't we be preascertaining?
shouldn't you be preascertaining?
shouldn't they be preascertaining? 	shouldn't I have preascertained?
shouldn't you have preascertained?
shouldn't he have preascertained?
shouldn't we have preascertained?
shouldn't you have preascertained?
shouldn't they have preascertained? 	shouldn't I have been preascertaining?
shouldn't you have been preascertaining?
shouldn't he have been preascertaining?
shouldn't we have been preascertaining?
shouldn't you have been preascertaining?
shouldn't they have been preascertaining?