should ascertain
Verbo regular: ascertain - ascertained- ascertained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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?