I could detach you could detach he could detach we could detach you could detach they could detach
V-ing form
I could be detaching you could be detaching he could be detaching we could be detaching you could be detaching they could be detaching
Perfect
I could have detached you could have detached he could have detached we could have detached you could have detached they could have detached
V-ing perfect
I could have been detaching you could have been detaching he could have been detaching we could have been detaching you could have been detaching they could have been detaching
Negation
Simple form
I couldn't detach you couldn't detach he couldn't detach we couldn't detach you couldn't detach they couldn't detach
V-ing form
I couldn't be detaching you couldn't be detaching he couldn't be detaching we couldn't be detaching you couldn't be detaching they couldn't be detaching
Perfect
I couldn't have detached you couldn't have detached he couldn't have detached we couldn't have detached you couldn't have detached they couldn't have detached
V-ing perfect
I couldn't have been detaching you couldn't have been detaching he couldn't have been detaching we couldn't have been detaching you couldn't have been detaching they couldn't have been detaching
Interrogative form
Simple form
could I detach? could you detach? could he detach? could we detach? could you detach? could they detach?
V-ing form
could I be detaching? could you be detaching? could he be detaching? could we be detaching? could you be detaching? could they be detaching?
Perfect
could I have detached? could you have detached? could he have detached? could we have detached? could you have detached? could they have detached?
V-ing perfect
could I have been detaching? could you have been detaching? could he have been detaching? could we have been detaching? could you have been detaching? could they have been detaching?
Interro-negative form
Simple form
couldn't I detach? couldn't you detach? couldn't he detach? couldn't we detach? couldn't you detach? couldn't they detach?
V-ing form
couldn't I be detaching? couldn't you be detaching? couldn't he be detaching? couldn't we be detaching? couldn't you be detaching? couldn't they be detaching?
Perfect
couldn't I have detached? couldn't you have detached? couldn't he have detached? couldn't we have detached? couldn't you have detached? couldn't they have detached?
V-ing perfect
couldn't I have been detaching? couldn't you have been detaching? couldn't he have been detaching? couldn't we have been detaching? couldn't you have been detaching? couldn't they have been detaching?