I could attempt you could attempt she could attempt we could attempt you could attempt they could attempt
V-ing form
I could be attempting you could be attempting she could be attempting we could be attempting you could be attempting they could be attempting
Perfect
I could have attempted you could have attempted she could have attempted we could have attempted you could have attempted they could have attempted
V-ing perfect
I could have been attempting you could have been attempting she could have been attempting we could have been attempting you could have been attempting they could have been attempting
Negation
Simple form
I could not attempt you could not attempt she could not attempt we could not attempt you could not attempt they could not attempt
V-ing form
I could not be attempting you could not be attempting she could not be attempting we could not be attempting you could not be attempting they could not be attempting
Perfect
I could not have attempted you could not have attempted she could not have attempted we could not have attempted you could not have attempted they could not have attempted
V-ing perfect
I could not have been attempting you could not have been attempting she could not have been attempting we could not have been attempting you could not have been attempting they could not have been attempting
Interrogative form
Simple form
could I attempt? could you attempt? could she attempt? could we attempt? could you attempt? could they attempt?
V-ing form
could I be attempting? could you be attempting? could she be attempting? could we be attempting? could you be attempting? could they be attempting?
Perfect
could I have attempted? could you have attempted? could she have attempted? could we have attempted? could you have attempted? could they have attempted?
V-ing perfect
could I have been attempting? could you have been attempting? could she have been attempting? could we have been attempting? could you have been attempting? could they have been attempting?
Interro-negative form
Simple form
could I not attempt? could you not attempt? could she not attempt? could we not attempt? could you not attempt? could they not attempt?
V-ing form
could I not be attempting? could you not be attempting? could she not be attempting? could we not be attempting? could you not be attempting? could they not be attempting?
Perfect
could I not have attempted? could you not have attempted? could she not have attempted? could we not have attempted? could you not have attempted? could they not have attempted?
V-ing perfect
could I not have been attempting? could you not have been attempting? could she not have been attempting? could we not have been attempting? could you not have been attempting? could they not have been attempting?