must corroborate
Verbo regular: corroborate - corroborated- corroborated

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

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't corroborate
you mustn't corroborate
he mustn't corroborate
we mustn't corroborate
you mustn't corroborate
they mustn't corroborate 	I mustn't be corroborating
you mustn't be corroborating
he mustn't be corroborating
we mustn't be corroborating
you mustn't be corroborating
they mustn't be corroborating	I mustn't have corroborated
you mustn't have corroborated
he mustn't have corroborated
we mustn't have corroborated
you mustn't have corroborated
they mustn't have corroborated	I mustn't have been corroborating
you mustn't have been corroborating
he mustn't have been corroborating
we mustn't have been corroborating
you mustn't have been corroborating
they mustn't have been corroborating	

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

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I corroborate?
mustn't you corroborate?
mustn't he corroborate?
mustn't we corroborate?
mustn't you corroborate?
mustn't they corroborate? 	mustn't I be corroborating?
mustn't you be corroborating?
mustn't he be corroborating?
mustn't we be corroborating?
mustn't you be corroborating?
mustn't they be corroborating? 	mustn't I have corroborated?
mustn't you have corroborated?
mustn't he have corroborated?
mustn't we have corroborated?
mustn't you have corroborated?
mustn't they have corroborated? 	mustn't I have been corroborating?
mustn't you have been corroborating?
mustn't he have been corroborating?
mustn't we have been corroborating?
mustn't you have been corroborating?
mustn't they have been corroborating?