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 couldn't beach you couldn't beach he couldn't beach we couldn't beach you couldn't beach they couldn't beach
V-ing form
I couldn't be beaching you couldn't be beaching he couldn't be beaching we couldn't be beaching you couldn't be beaching they couldn't be beaching
Perfect
I couldn't have beached you couldn't have beached he couldn't have beached we couldn't have beached you couldn't have beached they couldn't have beached
V-ing perfect
I couldn't have been beaching you couldn't have been beaching he couldn't have been beaching we couldn't have been beaching you couldn't have been beaching they couldn't 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
couldn't I beach? couldn't you beach? couldn't he beach? couldn't we beach? couldn't you beach? couldn't they beach?
V-ing form
couldn't I be beaching? couldn't you be beaching? couldn't he be beaching? couldn't we be beaching? couldn't you be beaching? couldn't they be beaching?
Perfect
couldn't I have beached? couldn't you have beached? couldn't he have beached? couldn't we have beached? couldn't you have beached? couldn't they have beached?
V-ing perfect
couldn't I have been beaching? couldn't you have been beaching? couldn't he have been beaching? couldn't we have been beaching? couldn't you have been beaching? couldn't they have been beaching?