I could throne you could throne he could throne we could throne you could throne they could throne
V-ing form
I could be throning you could be throning he could be throning we could be throning you could be throning they could be throning
Perfect
I could have throned you could have throned he could have throned we could have throned you could have throned they could have throned
V-ing perfect
I could have been throning you could have been throning he could have been throning we could have been throning you could have been throning they could have been throning
Negation
Simple form
I could not throne you could not throne he could not throne we could not throne you could not throne they could not throne
V-ing form
I could not be throning you could not be throning he could not be throning we could not be throning you could not be throning they could not be throning
Perfect
I could not have throned you could not have throned he could not have throned we could not have throned you could not have throned they could not have throned
V-ing perfect
I could not have been throning you could not have been throning he could not have been throning we could not have been throning you could not have been throning they could not have been throning
Interrogative form
Simple form
could I throne? could you throne? could he throne? could we throne? could you throne? could they throne?
V-ing form
could I be throning? could you be throning? could he be throning? could we be throning? could you be throning? could they be throning?
Perfect
could I have throned? could you have throned? could he have throned? could we have throned? could you have throned? could they have throned?
V-ing perfect
could I have been throning? could you have been throning? could he have been throning? could we have been throning? could you have been throning? could they have been throning?
Interro-negative form
Simple form
could I not throne? could you not throne? could he not throne? could we not throne? could you not throne? could they not throne?
V-ing form
could I not be throning? could you not be throning? could he not be throning? could we not be throning? could you not be throning? could they not be throning?
Perfect
could I not have throned? could you not have throned? could he not have throned? could we not have throned? could you not have throned? could they not have throned?
V-ing perfect
could I not have been throning? could you not have been throning? could he not have been throning? could we not have been throning? could you not have been throning? could they not have been throning?