could preascertain
Regular verb: preascertain - preascertained- preascertained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could preascertain
you could preascertain
she could preascertain
we could preascertain
you could preascertain
they could preascertain 	I could be preascertaining
you could be preascertaining
she could be preascertaining
we could be preascertaining
you could be preascertaining
they could be preascertaining	I could have preascertained
you could have preascertained
she could have preascertained
we could have preascertained
you could have preascertained
they could have preascertained	I could have been preascertaining
you could have been preascertaining
she could have been preascertaining
we could have been preascertaining
you could have been preascertaining
they could have been preascertaining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not preascertain
you could not preascertain
she could not preascertain
we could not preascertain
you could not preascertain
they could not preascertain 	I could not be preascertaining
you could not be preascertaining
she could not be preascertaining
we could not be preascertaining
you could not be preascertaining
they could not be preascertaining	I could not have preascertained
you could not have preascertained
she could not have preascertained
we could not have preascertained
you could not have preascertained
they could not have preascertained	I could not have been preascertaining
you could not have been preascertaining
she could not have been preascertaining
we could not have been preascertaining
you could not have been preascertaining
they could not have been preascertaining	

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

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not preascertain?
could you not preascertain?
could she not preascertain?
could we not preascertain?
could you not preascertain?
could they not preascertain? 	could I not be preascertaining?
could you not be preascertaining?
could she not be preascertaining?
could we not be preascertaining?
could you not be preascertaining?
could they not be preascertaining? 	could I not have preascertained?
could you not have preascertained?
could she not have preascertained?
could we not have preascertained?
could you not have preascertained?
could they not have preascertained? 	could I not have been preascertaining?
could you not have been preascertaining?
could she not have been preascertaining?
could we not have been preascertaining?
could you not have been preascertaining?
could they not have been preascertaining?