I can gridiron you can gridiron he can gridiron we can gridiron you can gridiron they can gridiron
V-ing form
I can be gridironing you can be gridironing he can be gridironing we can be gridironing you can be gridironing they can be gridironing
Perfect
I can have gridironed you can have gridironed he can have gridironed we can have gridironed you can have gridironed they can have gridironed
V-ing perfect
I can have been gridironing you can have been gridironing he can have been gridironing we can have been gridironing you can have been gridironing they can have been gridironing
Negation
Simple form
I cannot gridiron you cannot gridiron he cannot gridiron we cannot gridiron you cannot gridiron they cannot gridiron
V-ing form
I cannot be gridironing you cannot be gridironing he cannot be gridironing we cannot be gridironing you cannot be gridironing they cannot be gridironing
Perfect
I cannot have gridironed you cannot have gridironed he cannot have gridironed we cannot have gridironed you cannot have gridironed they cannot have gridironed
V-ing perfect
I cannot have been gridironing you cannot have been gridironing he cannot have been gridironing we cannot have been gridironing you cannot have been gridironing they cannot have been gridironing
Interrogative form
Simple form
can I gridiron? can you gridiron? can he gridiron? can we gridiron? can you gridiron? can they gridiron?
V-ing form
can I be gridironing? can you be gridironing? can he be gridironing? can we be gridironing? can you be gridironing? can they be gridironing?
Perfect
can I have gridironed? can you have gridironed? can he have gridironed? can we have gridironed? can you have gridironed? can they have gridironed?
V-ing perfect
can I have been gridironing? can you have been gridironing? can he have been gridironing? can we have been gridironing? can you have been gridironing? can they have been gridironing?
Interro-negative form
Simple form
can I not gridiron? can you not gridiron? can he not gridiron? can we not gridiron? can you not gridiron? can they not gridiron?
V-ing form
can I not be gridironing? can you not be gridironing? can he not be gridironing? can we not be gridironing? can you not be gridironing? can they not be gridironing?
Perfect
can I not have gridironed? can you not have gridironed? can he not have gridironed? can we not have gridironed? can you not have gridironed? can they not have gridironed?
V-ing perfect
can I not have been gridironing? can you not have been gridironing? can he not have been gridironing? can we not have been gridironing? can you not have been gridironing? can they not have been gridironing?