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 couldn't gum you couldn't gum he couldn't gum we couldn't gum you couldn't gum they couldn't gum	I couldn't be gumming you couldn't be gumming he couldn't be gumming we couldn't be gumming you couldn't be gumming they couldn't be gumming
Perfect	V-ing perfect
I couldn't have gummed you couldn't have gummed he couldn't have gummed we couldn't have gummed you couldn't have gummed they couldn't have gummed	I couldn't have been gumming you couldn't have been gumming he couldn't have been gumming we couldn't have been gumming you couldn't have been gumming they couldn't 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
couldn't I gum? couldn't you gum? couldn't he gum? couldn't we gum? couldn't you gum? couldn't they gum?	couldn't I be gumming? couldn't you be gumming? couldn't he be gumming? couldn't we be gumming? couldn't you be gumming? couldn't they be gumming?
Perfect	V-ing perfect
couldn't I have gummed? couldn't you have gummed? couldn't he have gummed? couldn't we have gummed? couldn't you have gummed? couldn't they have gummed?	couldn't I have been gumming? couldn't you have been gumming? couldn't he have been gumming? couldn't we have been gumming? couldn't you have been gumming? couldn't they have been gumming?