could circumstantiate
Regular verb: circumstantiate - circumstantiated- circumstantiated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could circumstantiate
you could circumstantiate
she could circumstantiate
we could circumstantiate
you could circumstantiate
they could circumstantiate 	I could be circumstantiating
you could be circumstantiating
she could be circumstantiating
we could be circumstantiating
you could be circumstantiating
they could be circumstantiating	I could have circumstantiated
you could have circumstantiated
she could have circumstantiated
we could have circumstantiated
you could have circumstantiated
they could have circumstantiated	I could have been circumstantiating
you could have been circumstantiating
she could have been circumstantiating
we could have been circumstantiating
you could have been circumstantiating
they could have been circumstantiating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't circumstantiate
you couldn't circumstantiate
she couldn't circumstantiate
we couldn't circumstantiate
you couldn't circumstantiate
they couldn't circumstantiate 	I couldn't be circumstantiating
you couldn't be circumstantiating
she couldn't be circumstantiating
we couldn't be circumstantiating
you couldn't be circumstantiating
they couldn't be circumstantiating	I couldn't have circumstantiated
you couldn't have circumstantiated
she couldn't have circumstantiated
we couldn't have circumstantiated
you couldn't have circumstantiated
they couldn't have circumstantiated	I couldn't have been circumstantiating
you couldn't have been circumstantiating
she couldn't have been circumstantiating
we couldn't have been circumstantiating
you couldn't have been circumstantiating
they couldn't have been circumstantiating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I circumstantiate?
could you circumstantiate?
could she circumstantiate?
could we circumstantiate?
could you circumstantiate?
could they circumstantiate? 	could I be circumstantiating?
could you be circumstantiating?
could she be circumstantiating?
could we be circumstantiating?
could you be circumstantiating?
could they be circumstantiating? 	could I have circumstantiated?
could you have circumstantiated?
could she have circumstantiated?
could we have circumstantiated?
could you have circumstantiated?
could they have circumstantiated? 	could I have been circumstantiating?
could you have been circumstantiating?
could she have been circumstantiating?
could we have been circumstantiating?
could you have been circumstantiating?
could they have been circumstantiating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I circumstantiate?
couldn't you circumstantiate?
couldn't she circumstantiate?
couldn't we circumstantiate?
couldn't you circumstantiate?
couldn't they circumstantiate? 	couldn't I be circumstantiating?
couldn't you be circumstantiating?
couldn't she be circumstantiating?
couldn't we be circumstantiating?
couldn't you be circumstantiating?
couldn't they be circumstantiating? 	couldn't I have circumstantiated?
couldn't you have circumstantiated?
couldn't she have circumstantiated?
couldn't we have circumstantiated?
couldn't you have circumstantiated?
couldn't they have circumstantiated? 	couldn't I have been circumstantiating?
couldn't you have been circumstantiating?
couldn't she have been circumstantiating?
couldn't we have been circumstantiating?
couldn't you have been circumstantiating?
couldn't they have been circumstantiating?