English verb conjugation
COULD INVOKE

Regular verb: invoke - invoked - invoked

Affirmation

Simple form	V-ing form
I could invoke you could invoke he could invoke we could invoke you could invoke they could invoke	I could be invoking you could be invoking he could be invoking we could be invoking you could be invoking they could be invoking
Perfect	V-ing perfect
I could have invoked you could have invoked he could have invoked we could have invoked you could have invoked they could have invoked	I could have been invoking you could have been invoking he could have been invoking we could have been invoking you could have been invoking they could have been invoking

Negation

Simple form	V-ing form
I couldn't invoke you couldn't invoke he couldn't invoke we couldn't invoke you couldn't invoke they couldn't invoke	I couldn't be invoking you couldn't be invoking he couldn't be invoking we couldn't be invoking you couldn't be invoking they couldn't be invoking
Perfect	V-ing perfect
I couldn't have invoked you couldn't have invoked he couldn't have invoked we couldn't have invoked you couldn't have invoked they couldn't have invoked	I couldn't have been invoking you couldn't have been invoking he couldn't have been invoking we couldn't have been invoking you couldn't have been invoking they couldn't have been invoking

Interrogative form

Simple form	V-ing form
could I invoke? could you invoke? could he invoke? could we invoke? could you invoke? could they invoke?	could I be invoking? could you be invoking? could he be invoking? could we be invoking? could you be invoking? could they be invoking?
Perfect	V-ing perfect
could I have invoked? could you have invoked? could he have invoked? could we have invoked? could you have invoked? could they have invoked?	could I have been invoking? could you have been invoking? could he have been invoking? could we have been invoking? could you have been invoking? could they have been invoking?

Interro-negative form

Simple form	V-ing form
couldn't I invoke? couldn't you invoke? couldn't he invoke? couldn't we invoke? couldn't you invoke? couldn't they invoke?	couldn't I be invoking? couldn't you be invoking? couldn't he be invoking? couldn't we be invoking? couldn't you be invoking? couldn't they be invoking?
Perfect	V-ing perfect
couldn't I have invoked? couldn't you have invoked? couldn't he have invoked? couldn't we have invoked? couldn't you have invoked? couldn't they have invoked?	couldn't I have been invoking? couldn't you have been invoking? couldn't he have been invoking? couldn't we have been invoking? couldn't you have been invoking? couldn't they have been invoking?