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