I could burn you could burn he could burn we could burn you could burn they could burn
V-ing form
I could be burning you could be burning he could be burning we could be burning you could be burning they could be burning
Perfect
I could have burned you could have burned he could have burned we could have burned you could have burned they could have burned
V-ing perfect
I could have been burning you could have been burning he could have been burning we could have been burning you could have been burning they could have been burning
Negation
Simple form
I could not burn you could not burn he could not burn we could not burn you could not burn they could not burn
V-ing form
I could not be burning you could not be burning he could not be burning we could not be burning you could not be burning they could not be burning
Perfect
I could not have burned you could not have burned he could not have burned we could not have burned you could not have burned they could not have burned
V-ing perfect
I could not have been burning you could not have been burning he could not have been burning we could not have been burning you could not have been burning they could not have been burning
Interrogative form
Simple form
could I burn? could you burn? could he burn? could we burn? could you burn? could they burn?
V-ing form
could I be burning? could you be burning? could he be burning? could we be burning? could you be burning? could they be burning?
Perfect
could I have burned? could you have burned? could he have burned? could we have burned? could you have burned? could they have burned?
V-ing perfect
could I have been burning? could you have been burning? could he have been burning? could we have been burning? could you have been burning? could they have been burning?
Interro-negative form
Simple form
could I not burn? could you not burn? could he not burn? could we not burn? could you not burn? could they not burn?
V-ing form
could I not be burning? could you not be burning? could he not be burning? could we not be burning? could you not be burning? could they not be burning?
Perfect
could I not have burned? could you not have burned? could he not have burned? could we not have burned? could you not have burned? could they not have burned?
V-ing perfect
could I not have been burning? could you not have been burning? could he not have been burning? could we not have been burning? could you not have been burning? could they not have been burning?