I could suppose you could suppose she could suppose we could suppose you could suppose they could suppose
V-ing form
I could be supposing you could be supposing she could be supposing we could be supposing you could be supposing they could be supposing
Perfect
I could have supposed you could have supposed she could have supposed we could have supposed you could have supposed they could have supposed
V-ing perfect
I could have been supposing you could have been supposing she could have been supposing we could have been supposing you could have been supposing they could have been supposing
Negation
Simple form
I could not suppose you could not suppose she could not suppose we could not suppose you could not suppose they could not suppose
V-ing form
I could not be supposing you could not be supposing she could not be supposing we could not be supposing you could not be supposing they could not be supposing
Perfect
I could not have supposed you could not have supposed she could not have supposed we could not have supposed you could not have supposed they could not have supposed
V-ing perfect
I could not have been supposing you could not have been supposing she could not have been supposing we could not have been supposing you could not have been supposing they could not have been supposing
Interrogative form
Simple form
could I suppose? could you suppose? could she suppose? could we suppose? could you suppose? could they suppose?
V-ing form
could I be supposing? could you be supposing? could she be supposing? could we be supposing? could you be supposing? could they be supposing?
Perfect
could I have supposed? could you have supposed? could she have supposed? could we have supposed? could you have supposed? could they have supposed?
V-ing perfect
could I have been supposing? could you have been supposing? could she have been supposing? could we have been supposing? could you have been supposing? could they have been supposing?
Interro-negative form
Simple form
could I not suppose? could you not suppose? could she not suppose? could we not suppose? could you not suppose? could they not suppose?
V-ing form
could I not be supposing? could you not be supposing? could she not be supposing? could we not be supposing? could you not be supposing? could they not be supposing?
Perfect
could I not have supposed? could you not have supposed? could she not have supposed? could we not have supposed? could you not have supposed? could they not have supposed?
V-ing perfect
could I not have been supposing? could you not have been supposing? could she not have been supposing? could we not have been supposing? could you not have been supposing? could they not have been supposing?