I could document you could document he could document we could document you could document they could document
V-ing form
I could be documenting you could be documenting he could be documenting we could be documenting you could be documenting they could be documenting
Perfect
I could have documented you could have documented he could have documented we could have documented you could have documented they could have documented
V-ing perfect
I could have been documenting you could have been documenting he could have been documenting we could have been documenting you could have been documenting they could have been documenting
Negation
Simple form
I could not document you could not document he could not document we could not document you could not document they could not document
V-ing form
I could not be documenting you could not be documenting he could not be documenting we could not be documenting you could not be documenting they could not be documenting
Perfect
I could not have documented you could not have documented he could not have documented we could not have documented you could not have documented they could not have documented
V-ing perfect
I could not have been documenting you could not have been documenting he could not have been documenting we could not have been documenting you could not have been documenting they could not have been documenting
Interrogative form
Simple form
could I document? could you document? could he document? could we document? could you document? could they document?
V-ing form
could I be documenting? could you be documenting? could he be documenting? could we be documenting? could you be documenting? could they be documenting?
Perfect
could I have documented? could you have documented? could he have documented? could we have documented? could you have documented? could they have documented?
V-ing perfect
could I have been documenting? could you have been documenting? could he have been documenting? could we have been documenting? could you have been documenting? could they have been documenting?
Interro-negative form
Simple form
could I not document? could you not document? could he not document? could we not document? could you not document? could they not document?
V-ing form
could I not be documenting? could you not be documenting? could he not be documenting? could we not be documenting? could you not be documenting? could they not be documenting?
Perfect
could I not have documented? could you not have documented? could he not have documented? could we not have documented? could you not have documented? could they not have documented?
V-ing perfect
could I not have been documenting? could you not have been documenting? could he not have been documenting? could we not have been documenting? could you not have been documenting? could they not have been documenting?