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