I could barber you could barber she could barber we could barber you could barber they could barber
V-ing form
I could be barbering you could be barbering she could be barbering we could be barbering you could be barbering they could be barbering
Perfect
I could have barbered you could have barbered she could have barbered we could have barbered you could have barbered they could have barbered
V-ing perfect
I could have been barbering you could have been barbering she could have been barbering we could have been barbering you could have been barbering they could have been barbering
Negation
Simple form
I could not barber you could not barber she could not barber we could not barber you could not barber they could not barber
V-ing form
I could not be barbering you could not be barbering she could not be barbering we could not be barbering you could not be barbering they could not be barbering
Perfect
I could not have barbered you could not have barbered she could not have barbered we could not have barbered you could not have barbered they could not have barbered
V-ing perfect
I could not have been barbering you could not have been barbering she could not have been barbering we could not have been barbering you could not have been barbering they could not have been barbering
Interrogative form
Simple form
could I barber? could you barber? could she barber? could we barber? could you barber? could they barber?
V-ing form
could I be barbering? could you be barbering? could she be barbering? could we be barbering? could you be barbering? could they be barbering?
Perfect
could I have barbered? could you have barbered? could she have barbered? could we have barbered? could you have barbered? could they have barbered?
V-ing perfect
could I have been barbering? could you have been barbering? could she have been barbering? could we have been barbering? could you have been barbering? could they have been barbering?
Interro-negative form
Simple form
could I not barber? could you not barber? could she not barber? could we not barber? could you not barber? could they not barber?
V-ing form
could I not be barbering? could you not be barbering? could she not be barbering? could we not be barbering? could you not be barbering? could they not be barbering?
Perfect
could I not have barbered? could you not have barbered? could she not have barbered? could we not have barbered? could you not have barbered? could they not have barbered?
V-ing perfect
could I not have been barbering? could you not have been barbering? could she not have been barbering? could we not have been barbering? could you not have been barbering? could they not have been barbering?