I could speak you could speak she could speak we could speak you could speak they could speak
V-ing form
I could be speaking you could be speaking she could be speaking we could be speaking you could be speaking they could be speaking
Perfect
I could have spoken, spoke you could have spoken, spoke she could have spoken, spoke we could have spoken, spoke you could have spoken, spoke they could have spoken, spoke
V-ing perfect
I could have been speaking you could have been speaking she could have been speaking we could have been speaking you could have been speaking they could have been speaking
Negation
Simple form
I could not speak you could not speak she could not speak we could not speak you could not speak they could not speak
V-ing form
I could not be speaking you could not be speaking she could not be speaking we could not be speaking you could not be speaking they could not be speaking
Perfect
I could not have spoken, spoke you could not have spoken, spoke she could not have spoken, spoke we could not have spoken, spoke you could not have spoken, spoke they could not have spoken, spoke
V-ing perfect
I could not have been speaking you could not have been speaking she could not have been speaking we could not have been speaking you could not have been speaking they could not have been speaking
Interrogative form
Simple form
could I speak? could you speak? could she speak? could we speak? could you speak? could they speak?
V-ing form
could I be speaking? could you be speaking? could she be speaking? could we be speaking? could you be speaking? could they be speaking?
Perfect
could I have spoken, spoke? could you have spoken, spoke? could she have spoken, spoke? could we have spoken, spoke? could you have spoken, spoke? could they have spoken, spoke?
V-ing perfect
could I have been speaking? could you have been speaking? could she have been speaking? could we have been speaking? could you have been speaking? could they have been speaking?
Interro-negative form
Simple form
could I not speak? could you not speak? could she not speak? could we not speak? could you not speak? could they not speak?
V-ing form
could I not be speaking? could you not be speaking? could she not be speaking? could we not be speaking? could you not be speaking? could they not be speaking?
Perfect
could I not have spoken, spoke? could you not have spoken, spoke? could she not have spoken, spoke? could we not have spoken, spoke? could you not have spoken, spoke? could they not have spoken, spoke?
V-ing perfect
could I not have been speaking? could you not have been speaking? could she not have been speaking? could we not have been speaking? could you not have been speaking? could they not have been speaking?