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 couldn't affirm you couldn't affirm he couldn't affirm we couldn't affirm you couldn't affirm they couldn't affirm
V-ing form
I couldn't be affirming you couldn't be affirming he couldn't be affirming we couldn't be affirming you couldn't be affirming they couldn't be affirming
Perfect
I couldn't have affirmed you couldn't have affirmed he couldn't have affirmed we couldn't have affirmed you couldn't have affirmed they couldn't have affirmed
V-ing perfect
I couldn't have been affirming you couldn't have been affirming he couldn't have been affirming we couldn't have been affirming you couldn't have been affirming they couldn't 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
couldn't I affirm? couldn't you affirm? couldn't he affirm? couldn't we affirm? couldn't you affirm? couldn't they affirm?
V-ing form
couldn't I be affirming? couldn't you be affirming? couldn't he be affirming? couldn't we be affirming? couldn't you be affirming? couldn't they be affirming?
Perfect
couldn't I have affirmed? couldn't you have affirmed? couldn't he have affirmed? couldn't we have affirmed? couldn't you have affirmed? couldn't they have affirmed?
V-ing perfect
couldn't I have been affirming? couldn't you have been affirming? couldn't he have been affirming? couldn't we have been affirming? couldn't you have been affirming? couldn't they have been affirming?