I could prove you could prove she could prove we could prove you could prove they could prove
V-ing form
I could be proving you could be proving she could be proving we could be proving you could be proving they could be proving
Perfect
I could have proven you could have proven she could have proven we could have proven you could have proven they could have proven
V-ing perfect
I could have been proving you could have been proving she could have been proving we could have been proving you could have been proving they could have been proving
Negation
Simple form
I couldn't prove you couldn't prove she couldn't prove we couldn't prove you couldn't prove they couldn't prove
V-ing form
I couldn't be proving you couldn't be proving she couldn't be proving we couldn't be proving you couldn't be proving they couldn't be proving
Perfect
I couldn't have proven you couldn't have proven she couldn't have proven we couldn't have proven you couldn't have proven they couldn't have proven
V-ing perfect
I couldn't have been proving you couldn't have been proving she couldn't have been proving we couldn't have been proving you couldn't have been proving they couldn't have been proving
Interrogative form
Simple form
could I prove? could you prove? could she prove? could we prove? could you prove? could they prove?
V-ing form
could I be proving? could you be proving? could she be proving? could we be proving? could you be proving? could they be proving?
Perfect
could I have proven? could you have proven? could she have proven? could we have proven? could you have proven? could they have proven?
V-ing perfect
could I have been proving? could you have been proving? could she have been proving? could we have been proving? could you have been proving? could they have been proving?
Interro-negative form
Simple form
couldn't I prove? couldn't you prove? couldn't she prove? couldn't we prove? couldn't you prove? couldn't they prove?
V-ing form
couldn't I be proving? couldn't you be proving? couldn't she be proving? couldn't we be proving? couldn't you be proving? couldn't they be proving?
Perfect
couldn't I have proven? couldn't you have proven? couldn't she have proven? couldn't we have proven? couldn't you have proven? couldn't they have proven?
V-ing perfect
couldn't I have been proving? couldn't you have been proving? couldn't she have been proving? couldn't we have been proving? couldn't you have been proving? couldn't they have been proving?