I could bar you could bar she could bar we could bar you could bar they could bar
V-ing form
I could be barring you could be barring she could be barring we could be barring you could be barring they could be barring
Perfect
I could have barred you could have barred she could have barred we could have barred you could have barred they could have barred
V-ing perfect
I could have been barring you could have been barring she could have been barring we could have been barring you could have been barring they could have been barring
Negation
Simple form
I could not bar you could not bar she could not bar we could not bar you could not bar they could not bar
V-ing form
I could not be barring you could not be barring she could not be barring we could not be barring you could not be barring they could not be barring
Perfect
I could not have barred you could not have barred she could not have barred we could not have barred you could not have barred they could not have barred
V-ing perfect
I could not have been barring you could not have been barring she could not have been barring we could not have been barring you could not have been barring they could not have been barring
Interrogative form
Simple form
could I bar? could you bar? could she bar? could we bar? could you bar? could they bar?
V-ing form
could I be barring? could you be barring? could she be barring? could we be barring? could you be barring? could they be barring?
Perfect
could I have barred? could you have barred? could she have barred? could we have barred? could you have barred? could they have barred?
V-ing perfect
could I have been barring? could you have been barring? could she have been barring? could we have been barring? could you have been barring? could they have been barring?
Interro-negative form
Simple form
could I not bar? could you not bar? could she not bar? could we not bar? could you not bar? could they not bar?
V-ing form
could I not be barring? could you not be barring? could she not be barring? could we not be barring? could you not be barring? could they not be barring?
Perfect
could I not have barred? could you not have barred? could she not have barred? could we not have barred? could you not have barred? could they not have barred?
V-ing perfect
could I not have been barring? could you not have been barring? could she not have been barring? could we not have been barring? could you not have been barring? could they not have been barring?