I could play you could play he could play we could play you could play they could play
V-ing form
I could be playing you could be playing he could be playing we could be playing you could be playing they could be playing
Perfect
I could have played you could have played he could have played we could have played you could have played they could have played
V-ing perfect
I could have been playing you could have been playing he could have been playing we could have been playing you could have been playing they could have been playing
Negation
Simple form
I could not play you could not play he could not play we could not play you could not play they could not play
V-ing form
I could not be playing you could not be playing he could not be playing we could not be playing you could not be playing they could not be playing
Perfect
I could not have played you could not have played he could not have played we could not have played you could not have played they could not have played
V-ing perfect
I could not have been playing you could not have been playing he could not have been playing we could not have been playing you could not have been playing they could not have been playing
Interrogative form
Simple form
could I play? could you play? could he play? could we play? could you play? could they play?
V-ing form
could I be playing? could you be playing? could he be playing? could we be playing? could you be playing? could they be playing?
Perfect
could I have played? could you have played? could he have played? could we have played? could you have played? could they have played?
V-ing perfect
could I have been playing? could you have been playing? could he have been playing? could we have been playing? could you have been playing? could they have been playing?
Interro-negative form
Simple form
could I not play? could you not play? could he not play? could we not play? could you not play? could they not play?
V-ing form
could I not be playing? could you not be playing? could he not be playing? could we not be playing? could you not be playing? could they not be playing?
Perfect
could I not have played? could you not have played? could he not have played? could we not have played? could you not have played? could they not have played?
V-ing perfect
could I not have been playing? could you not have been playing? could he not have been playing? could we not have been playing? could you not have been playing? could they not have been playing?