I could founder you could founder she could founder we could founder you could founder they could founder
V-ing form
I could be foundering you could be foundering she could be foundering we could be foundering you could be foundering they could be foundering
Perfect
I could have foundered you could have foundered she could have foundered we could have foundered you could have foundered they could have foundered
V-ing perfect
I could have been foundering you could have been foundering she could have been foundering we could have been foundering you could have been foundering they could have been foundering
Negation
Simple form
I could not founder you could not founder she could not founder we could not founder you could not founder they could not founder
V-ing form
I could not be foundering you could not be foundering she could not be foundering we could not be foundering you could not be foundering they could not be foundering
Perfect
I could not have foundered you could not have foundered she could not have foundered we could not have foundered you could not have foundered they could not have foundered
V-ing perfect
I could not have been foundering you could not have been foundering she could not have been foundering we could not have been foundering you could not have been foundering they could not have been foundering
Interrogative form
Simple form
could I founder? could you founder? could she founder? could we founder? could you founder? could they founder?
V-ing form
could I be foundering? could you be foundering? could she be foundering? could we be foundering? could you be foundering? could they be foundering?
Perfect
could I have foundered? could you have foundered? could she have foundered? could we have foundered? could you have foundered? could they have foundered?
V-ing perfect
could I have been foundering? could you have been foundering? could she have been foundering? could we have been foundering? could you have been foundering? could they have been foundering?
Interro-negative form
Simple form
could I not founder? could you not founder? could she not founder? could we not founder? could you not founder? could they not founder?
V-ing form
could I not be foundering? could you not be foundering? could she not be foundering? could we not be foundering? could you not be foundering? could they not be foundering?
Perfect
could I not have foundered? could you not have foundered? could she not have foundered? could we not have foundered? could you not have foundered? could they not have foundered?
V-ing perfect
could I not have been foundering? could you not have been foundering? could she not have been foundering? could we not have been foundering? could you not have been foundering? could they not have been foundering?