could corroborate
Verbo regular: corroborate - corroborated- corroborated

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could corroborate
you could corroborate
she could corroborate
we could corroborate
you could corroborate
they could corroborate 	I could be corroborating
you could be corroborating
she could be corroborating
we could be corroborating
you could be corroborating
they could be corroborating	I could have corroborated
you could have corroborated
she could have corroborated
we could have corroborated
you could have corroborated
they could have corroborated	I could have been corroborating
you could have been corroborating
she could have been corroborating
we could have been corroborating
you could have been corroborating
they could have been corroborating	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not corroborate
you could not corroborate
she could not corroborate
we could not corroborate
you could not corroborate
they could not corroborate 	I could not be corroborating
you could not be corroborating
she could not be corroborating
we could not be corroborating
you could not be corroborating
they could not be corroborating	I could not have corroborated
you could not have corroborated
she could not have corroborated
we could not have corroborated
you could not have corroborated
they could not have corroborated	I could not have been corroborating
you could not have been corroborating
she could not have been corroborating
we could not have been corroborating
you could not have been corroborating
they could not have been corroborating	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I corroborate?
could you corroborate?
could she corroborate?
could we corroborate?
could you corroborate?
could they corroborate? 	could I be corroborating?
could you be corroborating?
could she be corroborating?
could we be corroborating?
could you be corroborating?
could they be corroborating? 	could I have corroborated?
could you have corroborated?
could she have corroborated?
could we have corroborated?
could you have corroborated?
could they have corroborated? 	could I have been corroborating?
could you have been corroborating?
could she have been corroborating?
could we have been corroborating?
could you have been corroborating?
could they have been corroborating? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not corroborate?
could you not corroborate?
could she not corroborate?
could we not corroborate?
could you not corroborate?
could they not corroborate? 	could I not be corroborating?
could you not be corroborating?
could she not be corroborating?
could we not be corroborating?
could you not be corroborating?
could they not be corroborating? 	could I not have corroborated?
could you not have corroborated?
could she not have corroborated?
could we not have corroborated?
could you not have corroborated?
could they not have corroborated? 	could I not have been corroborating?
could you not have been corroborating?
could she not have been corroborating?
could we not have been corroborating?
could you not have been corroborating?
could they not have been corroborating?