I could borrow you could borrow he could borrow we could borrow you could borrow they could borrow
V-ing form
I could be borrowing you could be borrowing he could be borrowing we could be borrowing you could be borrowing they could be borrowing
Perfect
I could have borrowed you could have borrowed he could have borrowed we could have borrowed you could have borrowed they could have borrowed
V-ing perfect
I could have been borrowing you could have been borrowing he could have been borrowing we could have been borrowing you could have been borrowing they could have been borrowing
Negation
Simple form
I could not borrow you could not borrow he could not borrow we could not borrow you could not borrow they could not borrow
V-ing form
I could not be borrowing you could not be borrowing he could not be borrowing we could not be borrowing you could not be borrowing they could not be borrowing
Perfect
I could not have borrowed you could not have borrowed he could not have borrowed we could not have borrowed you could not have borrowed they could not have borrowed
V-ing perfect
I could not have been borrowing you could not have been borrowing he could not have been borrowing we could not have been borrowing you could not have been borrowing they could not have been borrowing
Interrogative form
Simple form
could I borrow? could you borrow? could he borrow? could we borrow? could you borrow? could they borrow?
V-ing form
could I be borrowing? could you be borrowing? could he be borrowing? could we be borrowing? could you be borrowing? could they be borrowing?
Perfect
could I have borrowed? could you have borrowed? could he have borrowed? could we have borrowed? could you have borrowed? could they have borrowed?
V-ing perfect
could I have been borrowing? could you have been borrowing? could he have been borrowing? could we have been borrowing? could you have been borrowing? could they have been borrowing?
Interro-negative form
Simple form
could I not borrow? could you not borrow? could he not borrow? could we not borrow? could you not borrow? could they not borrow?
V-ing form
could I not be borrowing? could you not be borrowing? could he not be borrowing? could we not be borrowing? could you not be borrowing? could they not be borrowing?
Perfect
could I not have borrowed? could you not have borrowed? could he not have borrowed? could we not have borrowed? could you not have borrowed? could they not have borrowed?
V-ing perfect
could I not have been borrowing? could you not have been borrowing? could he not have been borrowing? could we not have been borrowing? could you not have been borrowing? could they not have been borrowing?