I could bar you could bar he could bar we could bar you could bar they could bar
V-ing form
I could be barring you could be barring he could be barring we could be barring you could be barring they could be barring
Perfect
I could have barred you could have barred he 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 he could have been barring we could have been barring you could have been barring they could have been barring
Negation
Simple form
I couldn't bar you couldn't bar he couldn't bar we couldn't bar you couldn't bar they couldn't bar
V-ing form
I couldn't be barring you couldn't be barring he couldn't be barring we couldn't be barring you couldn't be barring they couldn't be barring
Perfect
I couldn't have barred you couldn't have barred he couldn't have barred we couldn't have barred you couldn't have barred they couldn't have barred
V-ing perfect
I couldn't have been barring you couldn't have been barring he couldn't have been barring we couldn't have been barring you couldn't have been barring they couldn't have been barring
Interrogative form
Simple form
could I bar? could you bar? could he bar? could we bar? could you bar? could they bar?
V-ing form
could I be barring? could you be barring? could he be barring? could we be barring? could you be barring? could they be barring?
Perfect
could I have barred? could you have barred? could he 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 he have been barring? could we have been barring? could you have been barring? could they have been barring?
Interro-negative form
Simple form
couldn't I bar? couldn't you bar? couldn't he bar? couldn't we bar? couldn't you bar? couldn't they bar?
V-ing form
couldn't I be barring? couldn't you be barring? couldn't he be barring? couldn't we be barring? couldn't you be barring? couldn't they be barring?
Perfect
couldn't I have barred? couldn't you have barred? couldn't he have barred? couldn't we have barred? couldn't you have barred? couldn't they have barred?
V-ing perfect
couldn't I have been barring? couldn't you have been barring? couldn't he have been barring? couldn't we have been barring? couldn't you have been barring? couldn't they have been barring?