I could choose you could choose she could choose we could choose you could choose they could choose
V-ing form
I could be choosing you could be choosing she could be choosing we could be choosing you could be choosing they could be choosing
Perfect
I could have chosen you could have chosen she could have chosen we could have chosen you could have chosen they could have chosen
V-ing perfect
I could have been choosing you could have been choosing she could have been choosing we could have been choosing you could have been choosing they could have been choosing
Negation
Simple form
I could not choose you could not choose she could not choose we could not choose you could not choose they could not choose
V-ing form
I could not be choosing you could not be choosing she could not be choosing we could not be choosing you could not be choosing they could not be choosing
Perfect
I could not have chosen you could not have chosen she could not have chosen we could not have chosen you could not have chosen they could not have chosen
V-ing perfect
I could not have been choosing you could not have been choosing she could not have been choosing we could not have been choosing you could not have been choosing they could not have been choosing
Interrogative form
Simple form
could I choose? could you choose? could she choose? could we choose? could you choose? could they choose?
V-ing form
could I be choosing? could you be choosing? could she be choosing? could we be choosing? could you be choosing? could they be choosing?
Perfect
could I have chosen? could you have chosen? could she have chosen? could we have chosen? could you have chosen? could they have chosen?
V-ing perfect
could I have been choosing? could you have been choosing? could she have been choosing? could we have been choosing? could you have been choosing? could they have been choosing?
Interro-negative form
Simple form
could I not choose? could you not choose? could she not choose? could we not choose? could you not choose? could they not choose?
V-ing form
could I not be choosing? could you not be choosing? could she not be choosing? could we not be choosing? could you not be choosing? could they not be choosing?
Perfect
could I not have chosen? could you not have chosen? could she not have chosen? could we not have chosen? could you not have chosen? could they not have chosen?
V-ing perfect
could I not have been choosing? could you not have been choosing? could she not have been choosing? could we not have been choosing? could you not have been choosing? could they not have been choosing?