I could surrender you could surrender he could surrender we could surrender you could surrender they could surrender
V-ing form
I could be surrendering you could be surrendering he could be surrendering we could be surrendering you could be surrendering they could be surrendering
Perfect
I could have surrendered you could have surrendered he could have surrendered we could have surrendered you could have surrendered they could have surrendered
V-ing perfect
I could have been surrendering you could have been surrendering he could have been surrendering we could have been surrendering you could have been surrendering they could have been surrendering
Negation
Simple form
I could not surrender you could not surrender he could not surrender we could not surrender you could not surrender they could not surrender
V-ing form
I could not be surrendering you could not be surrendering he could not be surrendering we could not be surrendering you could not be surrendering they could not be surrendering
Perfect
I could not have surrendered you could not have surrendered he could not have surrendered we could not have surrendered you could not have surrendered they could not have surrendered
V-ing perfect
I could not have been surrendering you could not have been surrendering he could not have been surrendering we could not have been surrendering you could not have been surrendering they could not have been surrendering
Interrogative form
Simple form
could I surrender? could you surrender? could he surrender? could we surrender? could you surrender? could they surrender?
V-ing form
could I be surrendering? could you be surrendering? could he be surrendering? could we be surrendering? could you be surrendering? could they be surrendering?
Perfect
could I have surrendered? could you have surrendered? could he have surrendered? could we have surrendered? could you have surrendered? could they have surrendered?
V-ing perfect
could I have been surrendering? could you have been surrendering? could he have been surrendering? could we have been surrendering? could you have been surrendering? could they have been surrendering?
Interro-negative form
Simple form
could I not surrender? could you not surrender? could he not surrender? could we not surrender? could you not surrender? could they not surrender?
V-ing form
could I not be surrendering? could you not be surrendering? could he not be surrendering? could we not be surrendering? could you not be surrendering? could they not be surrendering?
Perfect
could I not have surrendered? could you not have surrendered? could he not have surrendered? could we not have surrendered? could you not have surrendered? could they not have surrendered?
V-ing perfect
could I not have been surrendering? could you not have been surrendering? could he not have been surrendering? could we not have been surrendering? could you not have been surrendering? could they not have been surrendering?