English verb conjugation
COULD INVALID

Regular verb: invalid - invalided - invalided

Affirmation

Simple form	V-ing form
I could invalid you could invalid he could invalid we could invalid you could invalid they could invalid	I could be invaliding you could be invaliding he could be invaliding we could be invaliding you could be invaliding they could be invaliding
Perfect	V-ing perfect
I could have invalided you could have invalided he could have invalided we could have invalided you could have invalided they could have invalided	I could have been invaliding you could have been invaliding he could have been invaliding we could have been invaliding you could have been invaliding they could have been invaliding

Negation

Simple form	V-ing form
I couldn't invalid you couldn't invalid he couldn't invalid we couldn't invalid you couldn't invalid they couldn't invalid	I couldn't be invaliding you couldn't be invaliding he couldn't be invaliding we couldn't be invaliding you couldn't be invaliding they couldn't be invaliding
Perfect	V-ing perfect
I couldn't have invalided you couldn't have invalided he couldn't have invalided we couldn't have invalided you couldn't have invalided they couldn't have invalided	I couldn't have been invaliding you couldn't have been invaliding he couldn't have been invaliding we couldn't have been invaliding you couldn't have been invaliding they couldn't have been invaliding

Interrogative form

Simple form	V-ing form
could I invalid? could you invalid? could he invalid? could we invalid? could you invalid? could they invalid?	could I be invaliding? could you be invaliding? could he be invaliding? could we be invaliding? could you be invaliding? could they be invaliding?
Perfect	V-ing perfect
could I have invalided? could you have invalided? could he have invalided? could we have invalided? could you have invalided? could they have invalided?	could I have been invaliding? could you have been invaliding? could he have been invaliding? could we have been invaliding? could you have been invaliding? could they have been invaliding?

Interro-negative form

Simple form	V-ing form
couldn't I invalid? couldn't you invalid? couldn't he invalid? couldn't we invalid? couldn't you invalid? couldn't they invalid?	couldn't I be invaliding? couldn't you be invaliding? couldn't he be invaliding? couldn't we be invaliding? couldn't you be invaliding? couldn't they be invaliding?
Perfect	V-ing perfect
couldn't I have invalided? couldn't you have invalided? couldn't he have invalided? couldn't we have invalided? couldn't you have invalided? couldn't they have invalided?	couldn't I have been invaliding? couldn't you have been invaliding? couldn't he have been invaliding? couldn't we have been invaliding? couldn't you have been invaliding? couldn't they have been invaliding?