I could bit you could bit she could bit we could bit you could bit they could bit
V-ing form
I could be biting you could be biting she could be biting we could be biting you could be biting they could be biting
Perfect
I could have bited you could have bited she could have bited we could have bited you could have bited they could have bited
V-ing perfect
I could have been biting you could have been biting she could have been biting we could have been biting you could have been biting they could have been biting
Negation
Simple form
I could not bit you could not bit she could not bit we could not bit you could not bit they could not bit
V-ing form
I could not be biting you could not be biting she could not be biting we could not be biting you could not be biting they could not be biting
Perfect
I could not have bited you could not have bited she could not have bited we could not have bited you could not have bited they could not have bited
V-ing perfect
I could not have been biting you could not have been biting she could not have been biting we could not have been biting you could not have been biting they could not have been biting
Interrogative form
Simple form
could I bit? could you bit? could she bit? could we bit? could you bit? could they bit?
V-ing form
could I be biting? could you be biting? could she be biting? could we be biting? could you be biting? could they be biting?
Perfect
could I have bited? could you have bited? could she have bited? could we have bited? could you have bited? could they have bited?
V-ing perfect
could I have been biting? could you have been biting? could she have been biting? could we have been biting? could you have been biting? could they have been biting?
Interro-negative form
Simple form
could I not bit? could you not bit? could she not bit? could we not bit? could you not bit? could they not bit?
V-ing form
could I not be biting? could you not be biting? could she not be biting? could we not be biting? could you not be biting? could they not be biting?
Perfect
could I not have bited? could you not have bited? could she not have bited? could we not have bited? could you not have bited? could they not have bited?
V-ing perfect
could I not have been biting? could you not have been biting? could she not have been biting? could we not have been biting? could you not have been biting? could they not have been biting?