I could shadowbox you could shadowbox she could shadowbox we could shadowbox you could shadowbox they could shadowbox
V-ing form
I could be shadowboxing you could be shadowboxing she could be shadowboxing we could be shadowboxing you could be shadowboxing they could be shadowboxing
Perfect
I could have shadowboxed you could have shadowboxed she could have shadowboxed we could have shadowboxed you could have shadowboxed they could have shadowboxed
V-ing perfect
I could have been shadowboxing you could have been shadowboxing she could have been shadowboxing we could have been shadowboxing you could have been shadowboxing they could have been shadowboxing
Negation
Simple form
I could not shadowbox you could not shadowbox she could not shadowbox we could not shadowbox you could not shadowbox they could not shadowbox
V-ing form
I could not be shadowboxing you could not be shadowboxing she could not be shadowboxing we could not be shadowboxing you could not be shadowboxing they could not be shadowboxing
Perfect
I could not have shadowboxed you could not have shadowboxed she could not have shadowboxed we could not have shadowboxed you could not have shadowboxed they could not have shadowboxed
V-ing perfect
I could not have been shadowboxing you could not have been shadowboxing she could not have been shadowboxing we could not have been shadowboxing you could not have been shadowboxing they could not have been shadowboxing
Interrogative form
Simple form
could I shadowbox? could you shadowbox? could she shadowbox? could we shadowbox? could you shadowbox? could they shadowbox?
V-ing form
could I be shadowboxing? could you be shadowboxing? could she be shadowboxing? could we be shadowboxing? could you be shadowboxing? could they be shadowboxing?
Perfect
could I have shadowboxed? could you have shadowboxed? could she have shadowboxed? could we have shadowboxed? could you have shadowboxed? could they have shadowboxed?
V-ing perfect
could I have been shadowboxing? could you have been shadowboxing? could she have been shadowboxing? could we have been shadowboxing? could you have been shadowboxing? could they have been shadowboxing?
Interro-negative form
Simple form
could I not shadowbox? could you not shadowbox? could she not shadowbox? could we not shadowbox? could you not shadowbox? could they not shadowbox?
V-ing form
could I not be shadowboxing? could you not be shadowboxing? could she not be shadowboxing? could we not be shadowboxing? could you not be shadowboxing? could they not be shadowboxing?
Perfect
could I not have shadowboxed? could you not have shadowboxed? could she not have shadowboxed? could we not have shadowboxed? could you not have shadowboxed? could they not have shadowboxed?
V-ing perfect
could I not have been shadowboxing? could you not have been shadowboxing? could she not have been shadowboxing? could we not have been shadowboxing? could you not have been shadowboxing? could they not have been shadowboxing?