I could cab you could cab he could cab we could cab you could cab they could cab
V-ing form
I could be cabing you could be cabing he could be cabing we could be cabing you could be cabing they could be cabing
Perfect
I could have cabed you could have cabed he could have cabed we could have cabed you could have cabed they could have cabed
V-ing perfect
I could have been cabing you could have been cabing he could have been cabing we could have been cabing you could have been cabing they could have been cabing
Negation
Simple form
I could not cab you could not cab he could not cab we could not cab you could not cab they could not cab
V-ing form
I could not be cabing you could not be cabing he could not be cabing we could not be cabing you could not be cabing they could not be cabing
Perfect
I could not have cabed you could not have cabed he could not have cabed we could not have cabed you could not have cabed they could not have cabed
V-ing perfect
I could not have been cabing you could not have been cabing he could not have been cabing we could not have been cabing you could not have been cabing they could not have been cabing
Interrogative form
Simple form
could I cab? could you cab? could he cab? could we cab? could you cab? could they cab?
V-ing form
could I be cabing? could you be cabing? could he be cabing? could we be cabing? could you be cabing? could they be cabing?
Perfect
could I have cabed? could you have cabed? could he have cabed? could we have cabed? could you have cabed? could they have cabed?
V-ing perfect
could I have been cabing? could you have been cabing? could he have been cabing? could we have been cabing? could you have been cabing? could they have been cabing?
Interro-negative form
Simple form
could I not cab? could you not cab? could he not cab? could we not cab? could you not cab? could they not cab?
V-ing form
could I not be cabing? could you not be cabing? could he not be cabing? could we not be cabing? could you not be cabing? could they not be cabing?
Perfect
could I not have cabed? could you not have cabed? could he not have cabed? could we not have cabed? could you not have cabed? could they not have cabed?
V-ing perfect
could I not have been cabing? could you not have been cabing? could he not have been cabing? could we not have been cabing? could you not have been cabing? could they not have been cabing?