I could autograph you could autograph he could autograph we could autograph you could autograph they could autograph
V-ing form
I could be autographing you could be autographing he could be autographing we could be autographing you could be autographing they could be autographing
Perfect
I could have autographed you could have autographed he could have autographed we could have autographed you could have autographed they could have autographed
V-ing perfect
I could have been autographing you could have been autographing he could have been autographing we could have been autographing you could have been autographing they could have been autographing
Negation
Simple form
I could not autograph you could not autograph he could not autograph we could not autograph you could not autograph they could not autograph
V-ing form
I could not be autographing you could not be autographing he could not be autographing we could not be autographing you could not be autographing they could not be autographing
Perfect
I could not have autographed you could not have autographed he could not have autographed we could not have autographed you could not have autographed they could not have autographed
V-ing perfect
I could not have been autographing you could not have been autographing he could not have been autographing we could not have been autographing you could not have been autographing they could not have been autographing
Interrogative form
Simple form
could I autograph? could you autograph? could he autograph? could we autograph? could you autograph? could they autograph?
V-ing form
could I be autographing? could you be autographing? could he be autographing? could we be autographing? could you be autographing? could they be autographing?
Perfect
could I have autographed? could you have autographed? could he have autographed? could we have autographed? could you have autographed? could they have autographed?
V-ing perfect
could I have been autographing? could you have been autographing? could he have been autographing? could we have been autographing? could you have been autographing? could they have been autographing?
Interro-negative form
Simple form
could I not autograph? could you not autograph? could he not autograph? could we not autograph? could you not autograph? could they not autograph?
V-ing form
could I not be autographing? could you not be autographing? could he not be autographing? could we not be autographing? could you not be autographing? could they not be autographing?
Perfect
could I not have autographed? could you not have autographed? could he not have autographed? could we not have autographed? could you not have autographed? could they not have autographed?
V-ing perfect
could I not have been autographing? could you not have been autographing? could he not have been autographing? could we not have been autographing? could you not have been autographing? could they not have been autographing?