I can barn you can barn he can barn we can barn you can barn they can barn
V-ing form
I can be barning you can be barning he can be barning we can be barning you can be barning they can be barning
Perfect
I can have barned you can have barned he can have barned we can have barned you can have barned they can have barned
V-ing perfect
I can have been barning you can have been barning he can have been barning we can have been barning you can have been barning they can have been barning
Negation
Simple form
I cannot barn you cannot barn he cannot barn we cannot barn you cannot barn they cannot barn
V-ing form
I cannot be barning you cannot be barning he cannot be barning we cannot be barning you cannot be barning they cannot be barning
Perfect
I cannot have barned you cannot have barned he cannot have barned we cannot have barned you cannot have barned they cannot have barned
V-ing perfect
I cannot have been barning you cannot have been barning he cannot have been barning we cannot have been barning you cannot have been barning they cannot have been barning
Interrogative form
Simple form
can I barn? can you barn? can he barn? can we barn? can you barn? can they barn?
V-ing form
can I be barning? can you be barning? can he be barning? can we be barning? can you be barning? can they be barning?
Perfect
can I have barned? can you have barned? can he have barned? can we have barned? can you have barned? can they have barned?
V-ing perfect
can I have been barning? can you have been barning? can he have been barning? can we have been barning? can you have been barning? can they have been barning?
Interro-negative form
Simple form
can I not barn? can you not barn? can he not barn? can we not barn? can you not barn? can they not barn?
V-ing form
can I not be barning? can you not be barning? can he not be barning? can we not be barning? can you not be barning? can they not be barning?
Perfect
can I not have barned? can you not have barned? can he not have barned? can we not have barned? can you not have barned? can they not have barned?
V-ing perfect
can I not have been barning? can you not have been barning? can he not have been barning? can we not have been barning? can you not have been barning? can they not have been barning?