could preascertain
Verbo regular: preascertain - preascertained- preascertained

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could preascertain
you could preascertain
he could preascertain
we could preascertain
you could preascertain
they could preascertain 	I could be preascertaining
you could be preascertaining
he could be preascertaining
we could be preascertaining
you could be preascertaining
they could be preascertaining	I could have preascertained
you could have preascertained
he 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
he could have been preascertaining
we could have been preascertaining
you could have been preascertaining
they could have been preascertaining	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't preascertain
you couldn't preascertain
he couldn't preascertain
we couldn't preascertain
you couldn't preascertain
they couldn't preascertain 	I couldn't be preascertaining
you couldn't be preascertaining
he couldn't be preascertaining
we couldn't be preascertaining
you couldn't be preascertaining
they couldn't be preascertaining	I couldn't have preascertained
you couldn't have preascertained
he couldn't have preascertained
we couldn't have preascertained
you couldn't have preascertained
they couldn't have preascertained	I couldn't have been preascertaining
you couldn't have been preascertaining
he couldn't have been preascertaining
we couldn't have been preascertaining
you couldn't have been preascertaining
they couldn't have been preascertaining	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I preascertain?
could you preascertain?
could he preascertain?
could we preascertain?
could you preascertain?
could they preascertain? 	could I be preascertaining?
could you be preascertaining?
could he be preascertaining?
could we be preascertaining?
could you be preascertaining?
could they be preascertaining? 	could I have preascertained?
could you have preascertained?
could he 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 he have been preascertaining?
could we have been preascertaining?
could you have been preascertaining?
could they have been preascertaining? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I preascertain?
couldn't you preascertain?
couldn't he preascertain?
couldn't we preascertain?
couldn't you preascertain?
couldn't they preascertain? 	couldn't I be preascertaining?
couldn't you be preascertaining?
couldn't he be preascertaining?
couldn't we be preascertaining?
couldn't you be preascertaining?
couldn't they be preascertaining? 	couldn't I have preascertained?
couldn't you have preascertained?
couldn't he have preascertained?
couldn't we have preascertained?
couldn't you have preascertained?
couldn't they have preascertained? 	couldn't I have been preascertaining?
couldn't you have been preascertaining?
couldn't he have been preascertaining?
couldn't we have been preascertaining?
couldn't you have been preascertaining?
couldn't they have been preascertaining?