I could break you could break she could break we could break you could break they could break
V-ing form
I could be breaking you could be breaking she could be breaking we could be breaking you could be breaking they could be breaking
Perfect
I could have broken you could have broken she could have broken we could have broken you could have broken they could have broken
V-ing perfect
I could have been breaking you could have been breaking she could have been breaking we could have been breaking you could have been breaking they could have been breaking
Negation
Simple form
I could not break you could not break she could not break we could not break you could not break they could not break
V-ing form
I could not be breaking you could not be breaking she could not be breaking we could not be breaking you could not be breaking they could not be breaking
Perfect
I could not have broken you could not have broken she could not have broken we could not have broken you could not have broken they could not have broken
V-ing perfect
I could not have been breaking you could not have been breaking she could not have been breaking we could not have been breaking you could not have been breaking they could not have been breaking
Interrogative form
Simple form
could I break? could you break? could she break? could we break? could you break? could they break?
V-ing form
could I be breaking? could you be breaking? could she be breaking? could we be breaking? could you be breaking? could they be breaking?
Perfect
could I have broken? could you have broken? could she have broken? could we have broken? could you have broken? could they have broken?
V-ing perfect
could I have been breaking? could you have been breaking? could she have been breaking? could we have been breaking? could you have been breaking? could they have been breaking?
Interro-negative form
Simple form
could I not break? could you not break? could she not break? could we not break? could you not break? could they not break?
V-ing form
could I not be breaking? could you not be breaking? could she not be breaking? could we not be breaking? could you not be breaking? could they not be breaking?
Perfect
could I not have broken? could you not have broken? could she not have broken? could we not have broken? could you not have broken? could they not have broken?
V-ing perfect
could I not have been breaking? could you not have been breaking? could she not have been breaking? could we not have been breaking? could you not have been breaking? could they not have been breaking?