I could prove you could prove he could prove we could prove you could prove they could prove
V-ing form
I could be proving you could be proving he could be proving we could be proving you could be proving they could be proving
Perfect
I could have proven you could have proven he 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 he could have been proving we could have been proving you could have been proving they could have been proving
Negation
Simple form
I could not prove you could not prove he could not prove we could not prove you could not prove they could not prove
V-ing form
I could not be proving you could not be proving he could not be proving we could not be proving you could not be proving they could not be proving
Perfect
I could not have proven you could not have proven he could not have proven we could not have proven you could not have proven they could not have proven
V-ing perfect
I could not have been proving you could not have been proving he could not have been proving we could not have been proving you could not have been proving they could not have been proving
Interrogative form
Simple form
could I prove? could you prove? could he prove? could we prove? could you prove? could they prove?
V-ing form
could I be proving? could you be proving? could he be proving? could we be proving? could you be proving? could they be proving?
Perfect
could I have proven? could you have proven? could he 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 he have been proving? could we have been proving? could you have been proving? could they have been proving?
Interro-negative form
Simple form
could I not prove? could you not prove? could he not prove? could we not prove? could you not prove? could they not prove?
V-ing form
could I not be proving? could you not be proving? could he not be proving? could we not be proving? could you not be proving? could they not be proving?
Perfect
could I not have proven? could you not have proven? could he not have proven? could we not have proven? could you not have proven? could they not have proven?
V-ing perfect
could I not have been proving? could you not have been proving? could he not have been proving? could we not have been proving? could you not have been proving? could they not have been proving?