English verb conjugation
COULD GUM

Regular verb: gum - gummed - gummed

Affirmation

Simple form	V-ing form
I could gum you could gum he could gum we could gum you could gum they could gum	I could be gumming you could be gumming he could be gumming we could be gumming you could be gumming they could be gumming
Perfect	V-ing perfect
I could have gummed you could have gummed he could have gummed we could have gummed you could have gummed they could have gummed	I could have been gumming you could have been gumming he could have been gumming we could have been gumming you could have been gumming they could have been gumming

Negation

Simple form	V-ing form
I could not gum you could not gum he could not gum we could not gum you could not gum they could not gum	I could not be gumming you could not be gumming he could not be gumming we could not be gumming you could not be gumming they could not be gumming
Perfect	V-ing perfect
I could not have gummed you could not have gummed he could not have gummed we could not have gummed you could not have gummed they could not have gummed	I could not have been gumming you could not have been gumming he could not have been gumming we could not have been gumming you could not have been gumming they could not have been gumming

Interrogative form

Simple form	V-ing form
could I gum? could you gum? could he gum? could we gum? could you gum? could they gum?	could I be gumming? could you be gumming? could he be gumming? could we be gumming? could you be gumming? could they be gumming?
Perfect	V-ing perfect
could I have gummed? could you have gummed? could he have gummed? could we have gummed? could you have gummed? could they have gummed?	could I have been gumming? could you have been gumming? could he have been gumming? could we have been gumming? could you have been gumming? could they have been gumming?

Interro-negative form

Simple form	V-ing form
could I not gum? could you not gum? could he not gum? could we not gum? could you not gum? could they not gum?	could I not be gumming? could you not be gumming? could he not be gumming? could we not be gumming? could you not be gumming? could they not be gumming?
Perfect	V-ing perfect
could I not have gummed? could you not have gummed? could he not have gummed? could we not have gummed? could you not have gummed? could they not have gummed?	could I not have been gumming? could you not have been gumming? could he not have been gumming? could we not have been gumming? could you not have been gumming? could they not have been gumming?