I could threat you could threat he could threat we could threat you could threat they could threat
V-ing form
I could be threating you could be threating he could be threating we could be threating you could be threating they could be threating
Perfect
I could have threated you could have threated he could have threated we could have threated you could have threated they could have threated
V-ing perfect
I could have been threating you could have been threating he could have been threating we could have been threating you could have been threating they could have been threating
Negation
Simple form
I could not threat you could not threat he could not threat we could not threat you could not threat they could not threat
V-ing form
I could not be threating you could not be threating he could not be threating we could not be threating you could not be threating they could not be threating
Perfect
I could not have threated you could not have threated he could not have threated we could not have threated you could not have threated they could not have threated
V-ing perfect
I could not have been threating you could not have been threating he could not have been threating we could not have been threating you could not have been threating they could not have been threating
Interrogative form
Simple form
could I threat? could you threat? could he threat? could we threat? could you threat? could they threat?
V-ing form
could I be threating? could you be threating? could he be threating? could we be threating? could you be threating? could they be threating?
Perfect
could I have threated? could you have threated? could he have threated? could we have threated? could you have threated? could they have threated?
V-ing perfect
could I have been threating? could you have been threating? could he have been threating? could we have been threating? could you have been threating? could they have been threating?
Interro-negative form
Simple form
could I not threat? could you not threat? could he not threat? could we not threat? could you not threat? could they not threat?
V-ing form
could I not be threating? could you not be threating? could he not be threating? could we not be threating? could you not be threating? could they not be threating?
Perfect
could I not have threated? could you not have threated? could he not have threated? could we not have threated? could you not have threated? could they not have threated?
V-ing perfect
could I not have been threating? could you not have been threating? could he not have been threating? could we not have been threating? could you not have been threating? could they not have been threating?