ought to corroborate
Regular verb: corroborate - corroborated- corroborated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to corroborate
you ought to corroborate
she ought to corroborate
we ought to corroborate
you ought to corroborate
they ought to corroborate 	I ought to be corroborating
you ought to be corroborating
she ought to be corroborating
we ought to be corroborating
you ought to be corroborating
they ought to be corroborating	I ought to have corroborated
you ought to have corroborated
she ought to have corroborated
we ought to have corroborated
you ought to have corroborated
they ought to have corroborated	I ought to have been corroborating
you ought to have been corroborating
she ought to have been corroborating
we ought to have been corroborating
you ought to have been corroborating
they ought to have been corroborating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I oughtn't to corroborate
you oughtn't to corroborate
she oughtn't to corroborate
we oughtn't to corroborate
you oughtn't to corroborate
they oughtn't to corroborate 	I oughtn't to be corroborating
you oughtn't to be corroborating
she oughtn't to be corroborating
we oughtn't to be corroborating
you oughtn't to be corroborating
they oughtn't to be corroborating	I oughtn't to have corroborated
you oughtn't to have corroborated
she oughtn't to have corroborated
we oughtn't to have corroborated
you oughtn't to have corroborated
they oughtn't to have corroborated	I oughtn't to have been corroborating
you oughtn't to have been corroborating
she oughtn't to have been corroborating
we oughtn't to have been corroborating
you oughtn't to have been corroborating
they oughtn't to have been corroborating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I corroborate?
ought to you corroborate?
ought to she corroborate?
ought to we corroborate?
ought to you corroborate?
ought to they corroborate? 	ought to I be corroborating?
ought to you be corroborating?
ought to she be corroborating?
ought to we be corroborating?
ought to you be corroborating?
ought to they be corroborating? 	ought to I have corroborated?
ought to you have corroborated?
ought to she have corroborated?
ought to we have corroborated?
ought to you have corroborated?
ought to they have corroborated? 	ought to I have been corroborating?
ought to you have been corroborating?
ought to she have been corroborating?
ought to we have been corroborating?
ought to you have been corroborating?
ought to they have been corroborating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
oughtn't I to corroborate?
oughtn't you to corroborate?
oughtn't she to corroborate?
oughtn't we to corroborate?
oughtn't you to corroborate?
oughtn't they to corroborate? 	oughtn't I to be corroborating?
oughtn't you to be corroborating?
oughtn't she to be corroborating?
oughtn't we to be corroborating?
oughtn't you to be corroborating?
oughtn't they to be corroborating? 	oughtn't I to have corroborated?
oughtn't you to have corroborated?
oughtn't she to have corroborated?
oughtn't we to have corroborated?
oughtn't you to have corroborated?
oughtn't they to have corroborated? 	oughtn't I to have been corroborating?
oughtn't you to have been corroborating?
oughtn't she to have been corroborating?
oughtn't we to have been corroborating?
oughtn't you to have been corroborating?
oughtn't they to have been corroborating?