English verb conjugation
COULD NEGATE

Regular verb: negate - negated - negated

Affirmation

Simple form	V-ing form
I could negate you could negate he could negate we could negate you could negate they could negate	I could be negating you could be negating he could be negating we could be negating you could be negating they could be negating
Perfect	V-ing perfect
I could have negated you could have negated he could have negated we could have negated you could have negated they could have negated	I could have been negating you could have been negating he could have been negating we could have been negating you could have been negating they could have been negating

Negation

Simple form	V-ing form
I couldn't negate you couldn't negate he couldn't negate we couldn't negate you couldn't negate they couldn't negate	I couldn't be negating you couldn't be negating he couldn't be negating we couldn't be negating you couldn't be negating they couldn't be negating
Perfect	V-ing perfect
I couldn't have negated you couldn't have negated he couldn't have negated we couldn't have negated you couldn't have negated they couldn't have negated	I couldn't have been negating you couldn't have been negating he couldn't have been negating we couldn't have been negating you couldn't have been negating they couldn't have been negating

Interrogative form

Simple form	V-ing form
could I negate? could you negate? could he negate? could we negate? could you negate? could they negate?	could I be negating? could you be negating? could he be negating? could we be negating? could you be negating? could they be negating?
Perfect	V-ing perfect
could I have negated? could you have negated? could he have negated? could we have negated? could you have negated? could they have negated?	could I have been negating? could you have been negating? could he have been negating? could we have been negating? could you have been negating? could they have been negating?

Interro-negative form

Simple form	V-ing form
couldn't I negate? couldn't you negate? couldn't he negate? couldn't we negate? couldn't you negate? couldn't they negate?	couldn't I be negating? couldn't you be negating? couldn't he be negating? couldn't we be negating? couldn't you be negating? couldn't they be negating?
Perfect	V-ing perfect
couldn't I have negated? couldn't you have negated? couldn't he have negated? couldn't we have negated? couldn't you have negated? couldn't they have negated?	couldn't I have been negating? couldn't you have been negating? couldn't he have been negating? couldn't we have been negating? couldn't you have been negating? couldn't they have been negating?