English verb conjugation
COULD KEEN

Regular verb: keen - keened - keened

Affirmation

Simple form	V-ing form
I could keen you could keen he could keen we could keen you could keen they could keen	I could be keening you could be keening he could be keening we could be keening you could be keening they could be keening
Perfect	V-ing perfect
I could have keened you could have keened he could have keened we could have keened you could have keened they could have keened	I could have been keening you could have been keening he could have been keening we could have been keening you could have been keening they could have been keening

Negation

Simple form	V-ing form
I could not keen you could not keen he could not keen we could not keen you could not keen they could not keen	I could not be keening you could not be keening he could not be keening we could not be keening you could not be keening they could not be keening
Perfect	V-ing perfect
I could not have keened you could not have keened he could not have keened we could not have keened you could not have keened they could not have keened	I could not have been keening you could not have been keening he could not have been keening we could not have been keening you could not have been keening they could not have been keening

Interrogative form

Simple form	V-ing form
could I keen? could you keen? could he keen? could we keen? could you keen? could they keen?	could I be keening? could you be keening? could he be keening? could we be keening? could you be keening? could they be keening?
Perfect	V-ing perfect
could I have keened? could you have keened? could he have keened? could we have keened? could you have keened? could they have keened?	could I have been keening? could you have been keening? could he have been keening? could we have been keening? could you have been keening? could they have been keening?

Interro-negative form

Simple form	V-ing form
could I not keen? could you not keen? could he not keen? could we not keen? could you not keen? could they not keen?	could I not be keening? could you not be keening? could he not be keening? could we not be keening? could you not be keening? could they not be keening?
Perfect	V-ing perfect
could I not have keened? could you not have keened? could he not have keened? could we not have keened? could you not have keened? could they not have keened?	could I not have been keening? could you not have been keening? could he not have been keening? could we not have been keening? could you not have been keening? could they not have been keening?