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 couldn't speak you couldn't speak she couldn't speak we couldn't speak you couldn't speak they couldn't speak
V-ing form
I couldn't be speaking you couldn't be speaking she couldn't be speaking we couldn't be speaking you couldn't be speaking they couldn't be speaking
Perfect
I couldn't have spoken, spoke you couldn't have spoken, spoke she couldn't have spoken, spoke we couldn't have spoken, spoke you couldn't have spoken, spoke they couldn't have spoken, spoke
V-ing perfect
I couldn't have been speaking you couldn't have been speaking she couldn't have been speaking we couldn't have been speaking you couldn't have been speaking they couldn't 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
couldn't I speak? couldn't you speak? couldn't she speak? couldn't we speak? couldn't you speak? couldn't they speak?
V-ing form
couldn't I be speaking? couldn't you be speaking? couldn't she be speaking? couldn't we be speaking? couldn't you be speaking? couldn't they be speaking?
Perfect
couldn't I have spoken, spoke? couldn't you have spoken, spoke? couldn't she have spoken, spoke? couldn't we have spoken, spoke? couldn't you have spoken, spoke? couldn't they have spoken, spoke?
V-ing perfect
couldn't I have been speaking? couldn't you have been speaking? couldn't she have been speaking? couldn't we have been speaking? couldn't you have been speaking? couldn't they have been speaking?