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 couldn't threat you couldn't threat he couldn't threat we couldn't threat you couldn't threat they couldn't threat
V-ing form
I couldn't be threating you couldn't be threating he couldn't be threating we couldn't be threating you couldn't be threating they couldn't be threating
Perfect
I couldn't have threated you couldn't have threated he couldn't have threated we couldn't have threated you couldn't have threated they couldn't have threated
V-ing perfect
I couldn't have been threating you couldn't have been threating he couldn't have been threating we couldn't have been threating you couldn't have been threating they couldn't 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
couldn't I threat? couldn't you threat? couldn't he threat? couldn't we threat? couldn't you threat? couldn't they threat?
V-ing form
couldn't I be threating? couldn't you be threating? couldn't he be threating? couldn't we be threating? couldn't you be threating? couldn't they be threating?
Perfect
couldn't I have threated? couldn't you have threated? couldn't he have threated? couldn't we have threated? couldn't you have threated? couldn't they have threated?
V-ing perfect
couldn't I have been threating? couldn't you have been threating? couldn't he have been threating? couldn't we have been threating? couldn't you have been threating? couldn't they have been threating?