I could cram you could cram she could cram we could cram you could cram they could cram
V-ing form
I could be cramming you could be cramming she could be cramming we could be cramming you could be cramming they could be cramming
Perfect
I could have crammed you could have crammed she could have crammed we could have crammed you could have crammed they could have crammed
V-ing perfect
I could have been cramming you could have been cramming she could have been cramming we could have been cramming you could have been cramming they could have been cramming
Negation
Simple form
I could not cram you could not cram she could not cram we could not cram you could not cram they could not cram
V-ing form
I could not be cramming you could not be cramming she could not be cramming we could not be cramming you could not be cramming they could not be cramming
Perfect
I could not have crammed you could not have crammed she could not have crammed we could not have crammed you could not have crammed they could not have crammed
V-ing perfect
I could not have been cramming you could not have been cramming she could not have been cramming we could not have been cramming you could not have been cramming they could not have been cramming
Interrogative form
Simple form
could I cram? could you cram? could she cram? could we cram? could you cram? could they cram?
V-ing form
could I be cramming? could you be cramming? could she be cramming? could we be cramming? could you be cramming? could they be cramming?
Perfect
could I have crammed? could you have crammed? could she have crammed? could we have crammed? could you have crammed? could they have crammed?
V-ing perfect
could I have been cramming? could you have been cramming? could she have been cramming? could we have been cramming? could you have been cramming? could they have been cramming?
Interro-negative form
Simple form
could I not cram? could you not cram? could she not cram? could we not cram? could you not cram? could they not cram?
V-ing form
could I not be cramming? could you not be cramming? could she not be cramming? could we not be cramming? could you not be cramming? could they not be cramming?
Perfect
could I not have crammed? could you not have crammed? could she not have crammed? could we not have crammed? could you not have crammed? could they not have crammed?
V-ing perfect
could I not have been cramming? could you not have been cramming? could she not have been cramming? could we not have been cramming? could you not have been cramming? could they not have been cramming?