I could chop you could chop she could chop we could chop you could chop they could chop
V-ing form
I could be chopping you could be chopping she could be chopping we could be chopping you could be chopping they could be chopping
Perfect
I could have chopped you could have chopped she could have chopped we could have chopped you could have chopped they could have chopped
V-ing perfect
I could have been chopping you could have been chopping she could have been chopping we could have been chopping you could have been chopping they could have been chopping
Negation
Simple form
I could not chop you could not chop she could not chop we could not chop you could not chop they could not chop
V-ing form
I could not be chopping you could not be chopping she could not be chopping we could not be chopping you could not be chopping they could not be chopping
Perfect
I could not have chopped you could not have chopped she could not have chopped we could not have chopped you could not have chopped they could not have chopped
V-ing perfect
I could not have been chopping you could not have been chopping she could not have been chopping we could not have been chopping you could not have been chopping they could not have been chopping
Interrogative form
Simple form
could I chop? could you chop? could she chop? could we chop? could you chop? could they chop?
V-ing form
could I be chopping? could you be chopping? could she be chopping? could we be chopping? could you be chopping? could they be chopping?
Perfect
could I have chopped? could you have chopped? could she have chopped? could we have chopped? could you have chopped? could they have chopped?
V-ing perfect
could I have been chopping? could you have been chopping? could she have been chopping? could we have been chopping? could you have been chopping? could they have been chopping?
Interro-negative form
Simple form
could I not chop? could you not chop? could she not chop? could we not chop? could you not chop? could they not chop?
V-ing form
could I not be chopping? could you not be chopping? could she not be chopping? could we not be chopping? could you not be chopping? could they not be chopping?
Perfect
could I not have chopped? could you not have chopped? could she not have chopped? could we not have chopped? could you not have chopped? could they not have chopped?
V-ing perfect
could I not have been chopping? could you not have been chopping? could she not have been chopping? could we not have been chopping? could you not have been chopping? could they not have been chopping?