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 couldn't surrender you couldn't surrender he couldn't surrender we couldn't surrender you couldn't surrender they couldn't surrender
V-ing form
I couldn't be surrendering you couldn't be surrendering he couldn't be surrendering we couldn't be surrendering you couldn't be surrendering they couldn't be surrendering
Perfect
I couldn't have surrendered you couldn't have surrendered he couldn't have surrendered we couldn't have surrendered you couldn't have surrendered they couldn't have surrendered
V-ing perfect
I couldn't have been surrendering you couldn't have been surrendering he couldn't have been surrendering we couldn't have been surrendering you couldn't have been surrendering they couldn't 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
couldn't I surrender? couldn't you surrender? couldn't he surrender? couldn't we surrender? couldn't you surrender? couldn't they surrender?
V-ing form
couldn't I be surrendering? couldn't you be surrendering? couldn't he be surrendering? couldn't we be surrendering? couldn't you be surrendering? couldn't they be surrendering?
Perfect
couldn't I have surrendered? couldn't you have surrendered? couldn't he have surrendered? couldn't we have surrendered? couldn't you have surrendered? couldn't they have surrendered?
V-ing perfect
couldn't I have been surrendering? couldn't you have been surrendering? couldn't he have been surrendering? couldn't we have been surrendering? couldn't you have been surrendering? couldn't they have been surrendering?