English verb conjugation
COULD INVALIDATE

Regular verb: invalidate - invalidated - invalidated

Affirmation

Simple form	V-ing form
I could invalidate you could invalidate she could invalidate we could invalidate you could invalidate they could invalidate	I could be invalidating you could be invalidating she could be invalidating we could be invalidating you could be invalidating they could be invalidating
Perfect	V-ing perfect
I could have invalidated you could have invalidated she could have invalidated we could have invalidated you could have invalidated they could have invalidated	I could have been invalidating you could have been invalidating she could have been invalidating we could have been invalidating you could have been invalidating they could have been invalidating

Negation

Simple form	V-ing form
I could not invalidate you could not invalidate she could not invalidate we could not invalidate you could not invalidate they could not invalidate	I could not be invalidating you could not be invalidating she could not be invalidating we could not be invalidating you could not be invalidating they could not be invalidating
Perfect	V-ing perfect
I could not have invalidated you could not have invalidated she could not have invalidated we could not have invalidated you could not have invalidated they could not have invalidated	I could not have been invalidating you could not have been invalidating she could not have been invalidating we could not have been invalidating you could not have been invalidating they could not have been invalidating

Interrogative form

Simple form	V-ing form
could I invalidate? could you invalidate? could she invalidate? could we invalidate? could you invalidate? could they invalidate?	could I be invalidating? could you be invalidating? could she be invalidating? could we be invalidating? could you be invalidating? could they be invalidating?
Perfect	V-ing perfect
could I have invalidated? could you have invalidated? could she have invalidated? could we have invalidated? could you have invalidated? could they have invalidated?	could I have been invalidating? could you have been invalidating? could she have been invalidating? could we have been invalidating? could you have been invalidating? could they have been invalidating?

Interro-negative form

Simple form	V-ing form
could I not invalidate? could you not invalidate? could she not invalidate? could we not invalidate? could you not invalidate? could they not invalidate?	could I not be invalidating? could you not be invalidating? could she not be invalidating? could we not be invalidating? could you not be invalidating? could they not be invalidating?
Perfect	V-ing perfect
could I not have invalidated? could you not have invalidated? could she not have invalidated? could we not have invalidated? could you not have invalidated? could they not have invalidated?	could I not have been invalidating? could you not have been invalidating? could she not have been invalidating? could we not have been invalidating? could you not have been invalidating? could they not have been invalidating?