I could cover you could cover she could cover we could cover you could cover they could cover
V-ing form
I could be covering you could be covering she could be covering we could be covering you could be covering they could be covering
Perfect
I could have covered you could have covered she could have covered we could have covered you could have covered they could have covered
V-ing perfect
I could have been covering you could have been covering she could have been covering we could have been covering you could have been covering they could have been covering
Negation
Simple form
I could not cover you could not cover she could not cover we could not cover you could not cover they could not cover
V-ing form
I could not be covering you could not be covering she could not be covering we could not be covering you could not be covering they could not be covering
Perfect
I could not have covered you could not have covered she could not have covered we could not have covered you could not have covered they could not have covered
V-ing perfect
I could not have been covering you could not have been covering she could not have been covering we could not have been covering you could not have been covering they could not have been covering
Interrogative form
Simple form
could I cover? could you cover? could she cover? could we cover? could you cover? could they cover?
V-ing form
could I be covering? could you be covering? could she be covering? could we be covering? could you be covering? could they be covering?
Perfect
could I have covered? could you have covered? could she have covered? could we have covered? could you have covered? could they have covered?
V-ing perfect
could I have been covering? could you have been covering? could she have been covering? could we have been covering? could you have been covering? could they have been covering?
Interro-negative form
Simple form
could I not cover? could you not cover? could she not cover? could we not cover? could you not cover? could they not cover?
V-ing form
could I not be covering? could you not be covering? could she not be covering? could we not be covering? could you not be covering? could they not be covering?
Perfect
could I not have covered? could you not have covered? could she not have covered? could we not have covered? could you not have covered? could they not have covered?
V-ing perfect
could I not have been covering? could you not have been covering? could she not have been covering? could we not have been covering? could you not have been covering? could they not have been covering?