I could beach you could beach he could beach we could beach you could beach they could beach
V-ing form
I could be beaching you could be beaching he could be beaching we could be beaching you could be beaching they could be beaching
Perfect
I could have beached you could have beached he could have beached we could have beached you could have beached they could have beached
V-ing perfect
I could have been beaching you could have been beaching he could have been beaching we could have been beaching you could have been beaching they could have been beaching
Negation
Simple form
I could not beach you could not beach he could not beach we could not beach you could not beach they could not beach
V-ing form
I could not be beaching you could not be beaching he could not be beaching we could not be beaching you could not be beaching they could not be beaching
Perfect
I could not have beached you could not have beached he could not have beached we could not have beached you could not have beached they could not have beached
V-ing perfect
I could not have been beaching you could not have been beaching he could not have been beaching we could not have been beaching you could not have been beaching they could not have been beaching
Interrogative form
Simple form
could I beach? could you beach? could he beach? could we beach? could you beach? could they beach?
V-ing form
could I be beaching? could you be beaching? could he be beaching? could we be beaching? could you be beaching? could they be beaching?
Perfect
could I have beached? could you have beached? could he have beached? could we have beached? could you have beached? could they have beached?
V-ing perfect
could I have been beaching? could you have been beaching? could he have been beaching? could we have been beaching? could you have been beaching? could they have been beaching?
Interro-negative form
Simple form
could I not beach? could you not beach? could he not beach? could we not beach? could you not beach? could they not beach?
V-ing form
could I not be beaching? could you not be beaching? could he not be beaching? could we not be beaching? could you not be beaching? could they not be beaching?
Perfect
could I not have beached? could you not have beached? could he not have beached? could we not have beached? could you not have beached? could they not have beached?
V-ing perfect
could I not have been beaching? could you not have been beaching? could he not have been beaching? could we not have been beaching? could you not have been beaching? could they not have been beaching?