I could cite you could cite he could cite we could cite you could cite they could cite
V-ing form
I could be citing you could be citing he could be citing we could be citing you could be citing they could be citing
Perfect
I could have cited you could have cited he could have cited we could have cited you could have cited they could have cited
V-ing perfect
I could have been citing you could have been citing he could have been citing we could have been citing you could have been citing they could have been citing
Negation
Simple form
I could not cite you could not cite he could not cite we could not cite you could not cite they could not cite
V-ing form
I could not be citing you could not be citing he could not be citing we could not be citing you could not be citing they could not be citing
Perfect
I could not have cited you could not have cited he could not have cited we could not have cited you could not have cited they could not have cited
V-ing perfect
I could not have been citing you could not have been citing he could not have been citing we could not have been citing you could not have been citing they could not have been citing
Interrogative form
Simple form
could I cite? could you cite? could he cite? could we cite? could you cite? could they cite?
V-ing form
could I be citing? could you be citing? could he be citing? could we be citing? could you be citing? could they be citing?
Perfect
could I have cited? could you have cited? could he have cited? could we have cited? could you have cited? could they have cited?
V-ing perfect
could I have been citing? could you have been citing? could he have been citing? could we have been citing? could you have been citing? could they have been citing?
Interro-negative form
Simple form
could I not cite? could you not cite? could he not cite? could we not cite? could you not cite? could they not cite?
V-ing form
could I not be citing? could you not be citing? could he not be citing? could we not be citing? could you not be citing? could they not be citing?
Perfect
could I not have cited? could you not have cited? could he not have cited? could we not have cited? could you not have cited? could they not have cited?
V-ing perfect
could I not have been citing? could you not have been citing? could he not have been citing? could we not have been citing? could you not have been citing? could they not have been citing?