I could brake you could brake she could brake we could brake you could brake they could brake
V-ing form
I could be braking you could be braking she could be braking we could be braking you could be braking they could be braking
Perfect
I could have braked you could have braked she could have braked we could have braked you could have braked they could have braked
V-ing perfect
I could have been braking you could have been braking she could have been braking we could have been braking you could have been braking they could have been braking
Negation
Simple form
I could not brake you could not brake she could not brake we could not brake you could not brake they could not brake
V-ing form
I could not be braking you could not be braking she could not be braking we could not be braking you could not be braking they could not be braking
Perfect
I could not have braked you could not have braked she could not have braked we could not have braked you could not have braked they could not have braked
V-ing perfect
I could not have been braking you could not have been braking she could not have been braking we could not have been braking you could not have been braking they could not have been braking
Interrogative form
Simple form
could I brake? could you brake? could she brake? could we brake? could you brake? could they brake?
V-ing form
could I be braking? could you be braking? could she be braking? could we be braking? could you be braking? could they be braking?
Perfect
could I have braked? could you have braked? could she have braked? could we have braked? could you have braked? could they have braked?
V-ing perfect
could I have been braking? could you have been braking? could she have been braking? could we have been braking? could you have been braking? could they have been braking?
Interro-negative form
Simple form
could I not brake? could you not brake? could she not brake? could we not brake? could you not brake? could they not brake?
V-ing form
could I not be braking? could you not be braking? could she not be braking? could we not be braking? could you not be braking? could they not be braking?
Perfect
could I not have braked? could you not have braked? could she not have braked? could we not have braked? could you not have braked? could they not have braked?
V-ing perfect
could I not have been braking? could you not have been braking? could she not have been braking? could we not have been braking? could you not have been braking? could they not have been braking?