I could choke you could choke she could choke we could choke you could choke they could choke
V-ing form
I could be choking you could be choking she could be choking we could be choking you could be choking they could be choking
Perfect
I could have choked you could have choked she could have choked we could have choked you could have choked they could have choked
V-ing perfect
I could have been choking you could have been choking she could have been choking we could have been choking you could have been choking they could have been choking
Negation
Simple form
I could not choke you could not choke she could not choke we could not choke you could not choke they could not choke
V-ing form
I could not be choking you could not be choking she could not be choking we could not be choking you could not be choking they could not be choking
Perfect
I could not have choked you could not have choked she could not have choked we could not have choked you could not have choked they could not have choked
V-ing perfect
I could not have been choking you could not have been choking she could not have been choking we could not have been choking you could not have been choking they could not have been choking
Interrogative form
Simple form
could I choke? could you choke? could she choke? could we choke? could you choke? could they choke?
V-ing form
could I be choking? could you be choking? could she be choking? could we be choking? could you be choking? could they be choking?
Perfect
could I have choked? could you have choked? could she have choked? could we have choked? could you have choked? could they have choked?
V-ing perfect
could I have been choking? could you have been choking? could she have been choking? could we have been choking? could you have been choking? could they have been choking?
Interro-negative form
Simple form
could I not choke? could you not choke? could she not choke? could we not choke? could you not choke? could they not choke?
V-ing form
could I not be choking? could you not be choking? could she not be choking? could we not be choking? could you not be choking? could they not be choking?
Perfect
could I not have choked? could you not have choked? could she not have choked? could we not have choked? could you not have choked? could they not have choked?
V-ing perfect
could I not have been choking? could you not have been choking? could she not have been choking? could we not have been choking? could you not have been choking? could they not have been choking?