I could snap you could snap she could snap we could snap you could snap they could snap
V-ing form
I could be snapping you could be snapping she could be snapping we could be snapping you could be snapping they could be snapping
Perfect
I could have snapped you could have snapped she could have snapped we could have snapped you could have snapped they could have snapped
V-ing perfect
I could have been snapping you could have been snapping she could have been snapping we could have been snapping you could have been snapping they could have been snapping
Negation
Simple form
I could not snap you could not snap she could not snap we could not snap you could not snap they could not snap
V-ing form
I could not be snapping you could not be snapping she could not be snapping we could not be snapping you could not be snapping they could not be snapping
Perfect
I could not have snapped you could not have snapped she could not have snapped we could not have snapped you could not have snapped they could not have snapped
V-ing perfect
I could not have been snapping you could not have been snapping she could not have been snapping we could not have been snapping you could not have been snapping they could not have been snapping
Interrogative form
Simple form
could I snap? could you snap? could she snap? could we snap? could you snap? could they snap?
V-ing form
could I be snapping? could you be snapping? could she be snapping? could we be snapping? could you be snapping? could they be snapping?
Perfect
could I have snapped? could you have snapped? could she have snapped? could we have snapped? could you have snapped? could they have snapped?
V-ing perfect
could I have been snapping? could you have been snapping? could she have been snapping? could we have been snapping? could you have been snapping? could they have been snapping?
Interro-negative form
Simple form
could I not snap? could you not snap? could she not snap? could we not snap? could you not snap? could they not snap?
V-ing form
could I not be snapping? could you not be snapping? could she not be snapping? could we not be snapping? could you not be snapping? could they not be snapping?
Perfect
could I not have snapped? could you not have snapped? could she not have snapped? could we not have snapped? could you not have snapped? could they not have snapped?
V-ing perfect
could I not have been snapping? could you not have been snapping? could she not have been snapping? could we not have been snapping? could you not have been snapping? could they not have been snapping?