Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could attack attack you could attack attack he could attack attack we could attack attack you could attack attack they could attack attack
V-ing form
I could be attack attacking you could be attack attacking he could be attack attacking we could be attack attacking you could be attack attacking they could be attack attacking
Perfect
I could have attack attacked you could have attack attacked he could have attack attacked we could have attack attacked you could have attack attacked they could have attack attacked
V-ing perfect
I could have been attack attacking you could have been attack attacking he could have been attack attacking we could have been attack attacking you could have been attack attacking they could have been attack attacking
Negation
Simple form
I could not attack attack you could not attack attack he could not attack attack we could not attack attack you could not attack attack they could not attack attack
V-ing form
I could not be attack attacking you could not be attack attacking he could not be attack attacking we could not be attack attacking you could not be attack attacking they could not be attack attacking
Perfect
I could not have attack attacked you could not have attack attacked he could not have attack attacked we could not have attack attacked you could not have attack attacked they could not have attack attacked
V-ing perfect
I could not have been attack attacking you could not have been attack attacking he could not have been attack attacking we could not have been attack attacking you could not have been attack attacking they could not have been attack attacking
Interrogative form
Simple form
could I attack attack? could you attack attack? could he attack attack? could we attack attack? could you attack attack? could they attack attack?
V-ing form
could I be attack attacking? could you be attack attacking? could he be attack attacking? could we be attack attacking? could you be attack attacking? could they be attack attacking?
Perfect
could I have attack attacked? could you have attack attacked? could he have attack attacked? could we have attack attacked? could you have attack attacked? could they have attack attacked?
V-ing perfect
could I have been attack attacking? could you have been attack attacking? could he have been attack attacking? could we have been attack attacking? could you have been attack attacking? could they have been attack attacking?
Interro-negative form
Simple form
could I not attack attack? could you not attack attack? could he not attack attack? could we not attack attack? could you not attack attack? could they not attack attack?
V-ing form
could I not be attack attacking? could you not be attack attacking? could he not be attack attacking? could we not be attack attacking? could you not be attack attacking? could they not be attack attacking?
Perfect
could I not have attack attacked? could you not have attack attacked? could he not have attack attacked? could we not have attack attacked? could you not have attack attacked? could they not have attack attacked?
V-ing perfect
could I not have been attack attacking? could you not have been attack attacking? could he not have been attack attacking? could we not have been attack attacking? could you not have been attack attacking? could they not have been attack attacking?