I could affirm you could affirm he could affirm we could affirm you could affirm they could affirm
V-ing form
I could be affirming you could be affirming he could be affirming we could be affirming you could be affirming they could be affirming
Perfect
I could have affirmed you could have affirmed he could have affirmed we could have affirmed you could have affirmed they could have affirmed
V-ing perfect
I could have been affirming you could have been affirming he could have been affirming we could have been affirming you could have been affirming they could have been affirming
Negation
Simple form
I could not affirm you could not affirm he could not affirm we could not affirm you could not affirm they could not affirm
V-ing form
I could not be affirming you could not be affirming he could not be affirming we could not be affirming you could not be affirming they could not be affirming
Perfect
I could not have affirmed you could not have affirmed he could not have affirmed we could not have affirmed you could not have affirmed they could not have affirmed
V-ing perfect
I could not have been affirming you could not have been affirming he could not have been affirming we could not have been affirming you could not have been affirming they could not have been affirming
Interrogative form
Simple form
could I affirm? could you affirm? could he affirm? could we affirm? could you affirm? could they affirm?
V-ing form
could I be affirming? could you be affirming? could he be affirming? could we be affirming? could you be affirming? could they be affirming?
Perfect
could I have affirmed? could you have affirmed? could he have affirmed? could we have affirmed? could you have affirmed? could they have affirmed?
V-ing perfect
could I have been affirming? could you have been affirming? could he have been affirming? could we have been affirming? could you have been affirming? could they have been affirming?
Interro-negative form
Simple form
could I not affirm? could you not affirm? could he not affirm? could we not affirm? could you not affirm? could they not affirm?
V-ing form
could I not be affirming? could you not be affirming? could he not be affirming? could we not be affirming? could you not be affirming? could they not be affirming?
Perfect
could I not have affirmed? could you not have affirmed? could he not have affirmed? could we not have affirmed? could you not have affirmed? could they not have affirmed?
V-ing perfect
could I not have been affirming? could you not have been affirming? could he not have been affirming? could we not have been affirming? could you not have been affirming? could they not have been affirming?