could disprove
Regular verb: disprove - disproved- disproved

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could disprove
you could disprove
he could disprove
we could disprove
you could disprove
they could disprove 	I could be disproving
you could be disproving
he could be disproving
we could be disproving
you could be disproving
they could be disproving	I could have disproved
you could have disproved
he could have disproved
we could have disproved
you could have disproved
they could have disproved	I could have been disproving
you could have been disproving
he could have been disproving
we could have been disproving
you could have been disproving
they could have been disproving	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't disprove
you couldn't disprove
he couldn't disprove
we couldn't disprove
you couldn't disprove
they couldn't disprove 	I couldn't be disproving
you couldn't be disproving
he couldn't be disproving
we couldn't be disproving
you couldn't be disproving
they couldn't be disproving	I couldn't have disproved
you couldn't have disproved
he couldn't have disproved
we couldn't have disproved
you couldn't have disproved
they couldn't have disproved	I couldn't have been disproving
you couldn't have been disproving
he couldn't have been disproving
we couldn't have been disproving
you couldn't have been disproving
they couldn't have been disproving	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I disprove?
could you disprove?
could he disprove?
could we disprove?
could you disprove?
could they disprove? 	could I be disproving?
could you be disproving?
could he be disproving?
could we be disproving?
could you be disproving?
could they be disproving? 	could I have disproved?
could you have disproved?
could he have disproved?
could we have disproved?
could you have disproved?
could they have disproved? 	could I have been disproving?
could you have been disproving?
could he have been disproving?
could we have been disproving?
could you have been disproving?
could they have been disproving? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I disprove?
couldn't you disprove?
couldn't he disprove?
couldn't we disprove?
couldn't you disprove?
couldn't they disprove? 	couldn't I be disproving?
couldn't you be disproving?
couldn't he be disproving?
couldn't we be disproving?
couldn't you be disproving?
couldn't they be disproving? 	couldn't I have disproved?
couldn't you have disproved?
couldn't he have disproved?
couldn't we have disproved?
couldn't you have disproved?
couldn't they have disproved? 	couldn't I have been disproving?
couldn't you have been disproving?
couldn't he have been disproving?
couldn't we have been disproving?
couldn't you have been disproving?
couldn't they have been disproving?