Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could through you could through she could through we could through you could through they could through
V-ing form
I could be throughing you could be throughing she could be throughing we could be throughing you could be throughing they could be throughing
Perfect
I could have throughed you could have throughed she could have throughed we could have throughed you could have throughed they could have throughed
V-ing perfect
I could have been throughing you could have been throughing she could have been throughing we could have been throughing you could have been throughing they could have been throughing
Negation
Simple form
I could not through you could not through she could not through we could not through you could not through they could not through
V-ing form
I could not be throughing you could not be throughing she could not be throughing we could not be throughing you could not be throughing they could not be throughing
Perfect
I could not have throughed you could not have throughed she could not have throughed we could not have throughed you could not have throughed they could not have throughed
V-ing perfect
I could not have been throughing you could not have been throughing she could not have been throughing we could not have been throughing you could not have been throughing they could not have been throughing
Interrogative form
Simple form
could I through? could you through? could she through? could we through? could you through? could they through?
V-ing form
could I be throughing? could you be throughing? could she be throughing? could we be throughing? could you be throughing? could they be throughing?
Perfect
could I have throughed? could you have throughed? could she have throughed? could we have throughed? could you have throughed? could they have throughed?
V-ing perfect
could I have been throughing? could you have been throughing? could she have been throughing? could we have been throughing? could you have been throughing? could they have been throughing?
Interro-negative form
Simple form
could I not through? could you not through? could she not through? could we not through? could you not through? could they not through?
V-ing form
could I not be throughing? could you not be throughing? could she not be throughing? could we not be throughing? could you not be throughing? could they not be throughing?
Perfect
could I not have throughed? could you not have throughed? could she not have throughed? could we not have throughed? could you not have throughed? could they not have throughed?
V-ing perfect
could I not have been throughing? could you not have been throughing? could she not have been throughing? could we not have been throughing? could you not have been throughing? could they not have been throughing?