I can founder you can founder he can founder we can founder you can founder they can founder
V-ing form
I can be foundering you can be foundering he can be foundering we can be foundering you can be foundering they can be foundering
Perfect
I can have foundered you can have foundered he can have foundered we can have foundered you can have foundered they can have foundered
V-ing perfect
I can have been foundering you can have been foundering he can have been foundering we can have been foundering you can have been foundering they can have been foundering
Negation
Simple form
I can't founder you can't founder he can't founder we can't founder you can't founder they can't founder
V-ing form
I can't be foundering you can't be foundering he can't be foundering we can't be foundering you can't be foundering they can't be foundering
Perfect
I can't have foundered you can't have foundered he can't have foundered we can't have foundered you can't have foundered they can't have foundered
V-ing perfect
I can't have been foundering you can't have been foundering he can't have been foundering we can't have been foundering you can't have been foundering they can't have been foundering
Interrogative form
Simple form
can I founder? can you founder? can he founder? can we founder? can you founder? can they founder?
V-ing form
can I be foundering? can you be foundering? can he be foundering? can we be foundering? can you be foundering? can they be foundering?
Perfect
can I have foundered? can you have foundered? can he have foundered? can we have foundered? can you have foundered? can they have foundered?
V-ing perfect
can I have been foundering? can you have been foundering? can he have been foundering? can we have been foundering? can you have been foundering? can they have been foundering?
Interro-negative form
Simple form
can't I founder? can't you founder? can't he founder? can't we founder? can't you founder? can't they founder?
V-ing form
can't I be foundering? can't you be foundering? can't he be foundering? can't we be foundering? can't you be foundering? can't they be foundering?
Perfect
can't I have foundered? can't you have foundered? can't he have foundered? can't we have foundered? can't you have foundered? can't they have foundered?
V-ing perfect
can't I have been foundering? can't you have been foundering? can't he have been foundering? can't we have been foundering? can't you have been foundering? can't they have been foundering?