I could avenge you could avenge he could avenge we could avenge you could avenge they could avenge
V-ing form
I could be avenging you could be avenging he could be avenging we could be avenging you could be avenging they could be avenging
Perfect
I could have avenged you could have avenged he could have avenged we could have avenged you could have avenged they could have avenged
V-ing perfect
I could have been avenging you could have been avenging he could have been avenging we could have been avenging you could have been avenging they could have been avenging
Negation
Simple form
I couldn't avenge you couldn't avenge he couldn't avenge we couldn't avenge you couldn't avenge they couldn't avenge
V-ing form
I couldn't be avenging you couldn't be avenging he couldn't be avenging we couldn't be avenging you couldn't be avenging they couldn't be avenging
Perfect
I couldn't have avenged you couldn't have avenged he couldn't have avenged we couldn't have avenged you couldn't have avenged they couldn't have avenged
V-ing perfect
I couldn't have been avenging you couldn't have been avenging he couldn't have been avenging we couldn't have been avenging you couldn't have been avenging they couldn't have been avenging
Interrogative form
Simple form
could I avenge? could you avenge? could he avenge? could we avenge? could you avenge? could they avenge?
V-ing form
could I be avenging? could you be avenging? could he be avenging? could we be avenging? could you be avenging? could they be avenging?
Perfect
could I have avenged? could you have avenged? could he have avenged? could we have avenged? could you have avenged? could they have avenged?
V-ing perfect
could I have been avenging? could you have been avenging? could he have been avenging? could we have been avenging? could you have been avenging? could they have been avenging?
Interro-negative form
Simple form
couldn't I avenge? couldn't you avenge? couldn't he avenge? couldn't we avenge? couldn't you avenge? couldn't they avenge?
V-ing form
couldn't I be avenging? couldn't you be avenging? couldn't he be avenging? couldn't we be avenging? couldn't you be avenging? couldn't they be avenging?
Perfect
couldn't I have avenged? couldn't you have avenged? couldn't he have avenged? couldn't we have avenged? couldn't you have avenged? couldn't they have avenged?
V-ing perfect
couldn't I have been avenging? couldn't you have been avenging? couldn't he have been avenging? couldn't we have been avenging? couldn't you have been avenging? couldn't they have been avenging?