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