I could charm you could charm he could charm we could charm you could charm they could charm
V-ing form
I could be charming you could be charming he could be charming we could be charming you could be charming they could be charming
Perfect
I could have charmed you could have charmed he could have charmed we could have charmed you could have charmed they could have charmed
V-ing perfect
I could have been charming you could have been charming he could have been charming we could have been charming you could have been charming they could have been charming
Negation
Simple form
I could not charm you could not charm he could not charm we could not charm you could not charm they could not charm
V-ing form
I could not be charming you could not be charming he could not be charming we could not be charming you could not be charming they could not be charming
Perfect
I could not have charmed you could not have charmed he could not have charmed we could not have charmed you could not have charmed they could not have charmed
V-ing perfect
I could not have been charming you could not have been charming he could not have been charming we could not have been charming you could not have been charming they could not have been charming
Interrogative form
Simple form
could I charm? could you charm? could he charm? could we charm? could you charm? could they charm?
V-ing form
could I be charming? could you be charming? could he be charming? could we be charming? could you be charming? could they be charming?
Perfect
could I have charmed? could you have charmed? could he have charmed? could we have charmed? could you have charmed? could they have charmed?
V-ing perfect
could I have been charming? could you have been charming? could he have been charming? could we have been charming? could you have been charming? could they have been charming?
Interro-negative form
Simple form
could I not charm? could you not charm? could he not charm? could we not charm? could you not charm? could they not charm?
V-ing form
could I not be charming? could you not be charming? could he not be charming? could we not be charming? could you not be charming? could they not be charming?
Perfect
could I not have charmed? could you not have charmed? could he not have charmed? could we not have charmed? could you not have charmed? could they not have charmed?
V-ing perfect
could I not have been charming? could you not have been charming? could he not have been charming? could we not have been charming? could you not have been charming? could they not have been charming?